Multi-component rare earth garnet scintillator

Abstract

Multi-component rare earth garnet optical materials comprising at least three different rare earth elements and optionally activator ions are described. The optical material includes a rare earth garnet scintillator. Methods of making powders, ceramics and single crystals of optical materials are also described. In addition, a radiation detector comprising the rare earth garnet scintillator is described.

Description

[0001] Related Applications

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 63 / 343,885, filed on May 19, 2023; the disclosure of which is incorporated herein by reference in its entirety.

[0003] Parties to the Joint Research Agreement

[0004] The subject matter disclosed herein was performed by, on behalf of, and / or in connection with one or more of the parties to a joint research agreement between Siemens Medical Solutions USA, Inc. and the University of Tennessee. The agreement was in effect on and before the effective filing date of the presently disclosed subject matter, and the presently disclosed subject matter is the result of activities performed within the scope of the agreement. Technical Field

[0005] The presently disclosed subject matter relates to rare earth garnet optical materials comprising a combination of ions of at least three rare earth elements. The presently disclosed subject matter also relates to scintillators of the optical materials, radiation detectors comprising the scintillator materials, methods of detecting radiation using the scintillator materials, and methods of making the optical materials.

[0006] Abbreviations

[0007] % = Percent

[0008] ℃ = degrees Celsius

[0009] Al = Aluminum

[0010] at% = atomic percentage

[0011] au = arbitrary unit

[0012] CCD = Charge-coupled device

[0013] Ce = Cerium

[0014] cm = centimeters

[0015] CT = computed tomography

[0016] DI = Deionization

[0017] Dy=Dysprosium

[0018] Em = Emission

[0019] Er = Erbium

[0020] Eu=Europium

[0021] Exc = Excitation

[0022] g = grams

[0023] Ga=gallium

[0024] Gd=gadolinium

[0025] h = hours

[0026] Ho = holmium

[0027] keV = kiloelectronvolt

[0028] kVA = kilovolt-ampere

[0029] La = Lanthanum

[0030] Lu=Lutetium

[0031] LY = Light output

[0032] MeV = Million Electron Volts

[0033] min = minutes

[0034] ml = milliliters

[0035] mm = millimeters

[0036] mol = mole

[0037] mPa = megapascals

[0038] Nd = Neodymium

[0039] nm = nanometer

[0040] PEG = Polyethylene glycol

[0041] PET = Positron Emission Tomography

[0042] ph = photons

[0043] PL = Photoluminescence

[0044] Pm = Promethium

[0045] PMT = Photomultiplier tube

[0046] Pr = Praseodymium

[0047] PTFE = Polytetrafluoroethylene

[0048] PVA = Polyvinyl alcohol

[0049] RE = Rare Earth

[0050] RF = Radio Frequency

[0051] RL = Radiant Luminescence

[0052] Sc=scandium

[0053] Sm = Samarium

[0054] Tb = Terbium

[0055] Tm=Thulium

[0056] XRD = x-ray diffraction

[0057] Y = Yttrium

[0058] Yb=Ytterbium Background Art

[0059] Optical materials include phosphors and scintillators, which can emit light pulses when subjected to impact radiation such as X-rays, gamma rays, and neutrons. Compared with gas detectors and organic scintillators, inorganic scintillators are widely used in radiation detectors due to their high density and high atomic number. The radiation detectors have a wide range of applications in medical imaging, particle physics, geological exploration, homeland security and other related fields. These different applications use scintillators with suitable luminescent properties when used in different fields. Considerations when selecting scintillators and other optical materials generally include, but are not limited to, luminosity, decay time, and emission wavelength.

[0060] Although various optical materials have been developed, there remains a need to develop additional optical materials with improved properties for specific applications. Summary of the invention

[0061] This summary lists several embodiments of the presently disclosed subject matter, and in many cases lists variations and permutations of these embodiments. This summary is merely an example of the numerous different embodiments. Mentioning one or more representative features of a given embodiment is likewise exemplary. Such an embodiment may generally have or not have the features described; likewise, these features may be applied to other embodiments of the presently disclosed subject matter, whether or not listed in this summary. To avoid excessive repetition, this summary does not list or suggest all possible combinations of such features.

[0062] In some embodiments, the presently disclosed subject matter provides an optical material comprising a composition of the formula:

[0063] (RE 1-y X y )3(Al 1-z Ga z )5O 12 ,

[0064] Wherein: 0≤y≤0.1; 0≤z≤1; RE is a combination of ions of three or more rare earth elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La; and X is one or more activator ions selected from the group consisting of Ce ions, Tb ions, Dy ions, Eu ions, Yb ions and Pr ions. In some embodiments, z is 0.

[0065] In some embodiments, RE is a combination of ions of three, four, five, or six elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr, and La. In some embodiments, RE is a combination of ions of at least three elements selected from the group consisting of Y, Lu, Tb, and Gd.

[0066] In some embodiments, y is 0. In some embodiments, 0.001≤y≤0.1. In some embodiments, 0.005≤y≤0.05; optionally wherein y is 0.005, 0.02 or 0.05. In some embodiments, X is Ce ion, Pr ion or a mixture thereof, optionally wherein X is Ce 3+ .

[0067] In some embodiments, the optical material comprises a component selected from the group consisting of:

[0068] (Y 0.2 G 0.2 Tb 0.2 Y 0.2 Lu 0.2 )3Al5O 12 ;

[0069] (Y 0.25 G 0.25 Er 0.25 Lu 0.25 )3Al5O 12 ;

[0070] (Y 0.25 G 0.25 Ho 0.25 Lu 0.25 )3Al5O 12 ;

[0071] (Y 0.2 G 0.2 Tb 0.2 Dy 0.2 Lu 0.2 )3Al5O 12 ;

[0072] (Y0.25 G 0.25 Tb 0.25 Lu 0.25 )3Al5O 12 ;

[0073] (Y 0.2 Eu 0.2 G 0.2 Yb 0.2 Lu 0.2 )3Al5O 12 ;

[0074] (Y 0.1667 Eu 0.1667 G 0.1667 Tb 0.1667 Yb 0.1667 Lu 0.1667 )3Al5O 12 ;

[0075] (Y 0.25 G 0.25 Tb 0.25 Lu 0.25 )3Al5O 12 ;

[0076] (Y 0.25 Nd 0.25 G 0.25 Lu 0.25 )3Al5O 12 ;

[0077] (Y 0.25 Pr 0.25 G 0.25 Lu 0.25 )3Al5O 12 ;and

[0078] (Y 0.25 La 0.25 G 0.25 Lu 0.25 )3Al5O 12 .

[0079] In some embodiments, the optical material comprises a component selected from the group consisting of:

[0080] (Y 0.199 G 0.199 Tb 0.199 Yb 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 ;

[0081] (Y 0.24875 G 0.24875<h2 style=";text-align:left;direction:ltr">Er<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0082] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ho<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0083] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Dy<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0084] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0085] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Eu<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Yb<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0086] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.16583 <h2 style=";text-align:left;direction:ltr"> Eu<h2 style=";text-align:left;direction:ltr"> 0.16583 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.16583 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.16583 <h2 style=";text-align:left;direction:ltr"> Yb<h2 style=";text-align:left;direction:ltr"> 0.16583 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.16583 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0087] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Sm<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0088] <h2 style=";text-align:left;direction:ltr"> (Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Nd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ;<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0089] <h2 style=";text-align:left;direction:ltr"> (Y0.24875 Pr 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0090] (Y 0.24875 La 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0091] (Y 0.245 G 0.245 Tb 0.245 Lu 0.245 Ce 0.02 )3Al5O 12 ;

[0092] (Y 0.2375 G 0.2375 Tb 0.2375 Lu 0.2375 Ce 0.05 )3Al5O 12 ;

[0093] (Y 0.2375 G 0.2375 Tb 0.2375 Lu 0.2375 Ce 0.05 )3Al5O 12 ;and

[0094] (Y 0.294 G 0.294 Tb 0.098 Lu 0.294 Ce 0.02 )3Al5O 12 .

[0095] In some embodiments, the optical material comprises a component selected from the group consisting of:

[0096] (Y 0.33167 Tb 0.33167 G 0.33167 Ce 0.005 )3Al5O 12 ;

[0097] (Lu 0.33167 Y 0.33167 G 0.33167 Ce 0.005 )3Al5O 12 ;

[0098] (Lu0.33167 Y 0.33167 Tb 0.33167 Ce 0.005 )3Al5O 12 ;

[0099] (Lu 0.24875 Y 0.24875 Tb 0.24875 G 0.24875 Ce 0.005 )3Al5O 12 ;and

[0100] (Lu 0.245 Y 0.245 Tb 0.245 G 0.245 Ce 0.02 )3Al5O 12 .

[0101] In some embodiments, the optical material provides light emission from photoactive RE ions upon stimulation of the optical material with high energy radiation, optionally wherein the photoactive RE ions are Tb ions.

[0102] In some embodiments, the presently disclosed subject matter provides a radiation detector comprising an optical material of the presently disclosed subject matter and a photon detector, optionally wherein the optical material comprises a composition selected from the group comprising:

[0103] (Y 0.33167 Tb 0.33167 G 0.33167 Ce 0.005 )3Al5O 12 ;

[0104] (Lu 0.33167 Y 0.33167 G 0.33167 Ce 0.005 )3Al5O 12 ;

[0105] (Lu 0.33167 Y 0.33167 Tb 0.33167 Ce 0.005 )3Al5O 12 ;

[0106] (Lu 0.24875 Y 0.24875 Tb 0.24875 G 0.24875 Ce 0.005 )3Al5O 12 ;and

[0107] (Lu 0.245 Y 0.245Tb 0.245 G 0.245 Ce 0.02 )3Al5O 12 .

[0108] In some embodiments, the presently disclosed subject matter provides a method of detecting gamma rays, X-rays, cosmic rays, and / or particles having energies of 1 keV or greater, the method comprising using a radiation detector. In some embodiments, the presently disclosed subject matter provides for the use of radiation detectors in medical imaging, homeland security, or high energy physics research.

[0109] In some embodiments, the presently disclosed subject matter provides a method of preparing an optical material of the presently disclosed subject matter, wherein the method comprises preparing a single crystal of the optical material from a melt.

[0110] In some embodiments, the presently disclosed subject matter provides a method for preparing an optical material of the presently disclosed subject matter, wherein the method comprises preparing a powder of the optical material by the following steps: (i) preparing a foam by heating an aqueous solution comprising a mixture of a polymer, optionally polyvinyl alcohol (PVA) or polyethylene glycol (PEG), and a metal nitrate, wherein the metal nitrate comprises elemental ions corresponding to the element of the optical material, and pulverizing the foam to provide a powder; or (ii) co-precipitating a powder by adding an aqueous solution comprising a mixture of a metal nitrate and ammonium sulfate to an aqueous ammonium carbonate solution, wherein the metal nitrate comprises elemental ions corresponding to the element of the optical material.

[0111] In some embodiments, the presently disclosed subject matter provides a method of preparing an optical material of the presently disclosed subject matter, wherein the method comprises preparing a ceramic of the optical material by a technique selected from the following.

[0112] It is an object of the presently disclosed subject matter to provide multi-component rare earth garnet optical materials, such as scintillators, radiation detectors containing the optical materials, methods of using the radiation detectors, and methods of making the optical materials.

[0113] The objects of the presently disclosed subject matter have been stated above and are wholly or partially achieved by the presently disclosed subject matter, and other objects will become apparent after reading the specification and when described in conjunction with the drawings and examples best described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] Figure 1 Composite photographic images of crystals of exemplary rare earth garnet compositions of the presently disclosed subject matter: (1) (Lu 1 / 3 Y 1 / 3 G 1 / 3 )3Al5O 12:Ce 0.5%, (2)(Lu 1 / 3 Y 1 / 3 Tb 1 / 3 )3Al5O 12 :Ce0.5%,(3)(Y 1 / 3 Tb 1 / 3 G 1 / 3 )3Al5O 12 :Ce 0.5%, (4)(Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce 0.5%, (5)(Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce2%, and (6)(Lu 1 / 5 Y 1 / 5 Dy 1 / 5 Tb 1 / 5 G 1 / 5 )3Al5O 12 :Ce 0.5%. All crystals are transparent yellow. The scale bar in the upper left corner represents 1 centimeter (cm).

[0115] Figure 2 Composite photographic images of green body particles (1-6) and hot pressed particles (7) of ceramics of exemplary rare earth garnet compositions of the presently disclosed subject matter. The numbers in the images correspond to the following compositions: (1) (Y 1 / 4 Sm 1 / 4 G 1 / 4Lu 1 / 4 )3Al5O 12 :Ce 0.5%;(2)(Y 1 / 4 Nd 1 / 4 G 1 / 4 Lu 1 / 4 )3Al5O 12 :Ce 0.5%;(3)(Y 1 / 4 Pr 1 / 4 G 1 / 4Lu 1 / 4 )3Al5O 12 :Ce0.5%;(4)(Y 1 / 4 Sm 1 / 4 G 1 / 4 Lu 1 / 4 )3Al5O 12 ; (5)(Y 1 / 4 Nd 1 / 4 G 1 / 4 Lu1 / 4 ) 3Al5O 12 ; (6)(Y 1 / 4 Pr 1 / 4 Gd 1 / 4 Lu 1 / 4 ) 3Al5O 12 ; and (7)(Y 1 / 4 Gd 1 / 4 Tb 1 / 4 Lu 1 / 4 ) 3Al5O 12 : Ce 2%.

[0116] Figure 3 is a diagram showing the room temperature X-ray diffraction (XRD) patterns (intensity in arbitrary units (a.u.) and 2θ angle in degrees (°)) of the multi-component (RE 1-x Ce x ) 3Al5O 12 components of the presently disclosed subject matter. From top to bottom, the XRD pattern is: (Lu 1 / 6 Y 1 / 6 Ho 1 / 6 Dy 1 / 6 Tb 1 / 6 Gd 1 / 6 ) 3Al5O 12 : Ce; (Lu 1 / 5 Y 1 / 5 Dy 1 / 5 Tb 1 / 5 Gd 1 / 5 ) 3Al5O 12 : Ce; (Lu 1 / 4 Y 1 / 4 Dy 1 / 4Gd 1 / 4 ) 3Al5O 12 : Ce; and (Lu 1 / 3 Y 1 / 3 Gd 1 / 3 ) 3Al5O 12 : Ce. The pattern of Lu3Al5O 12 is plotted (see reference [1]) for comparison.

[0117] Figure 4A is a diagram showing the emission (Em) and excitation (Exc) spectra (intensity in arbitrary units (a.u.) and wavelength in nanometers (nm)) of exemplary rare earth garnets of the presently disclosed subject matter: (Lu 1 / 3 Y 1 / 3 Gd 1 / 3 ) 3Al5O 12:Ce0.5%. The dotted line is the Exc spectrum at 545nm Em. The lighter solid line is the Em spectrum at 448nm Exc, and the darker solid line is the Em spectrum at 341nm Exc.

[0118] Figure 4B is a graph showing the emission (Em) and excitation (Exc) spectra (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet of the presently disclosed subject matter: (Y 1 / 3 Tb 1 / 3 G 1 / 3 )3Al5O 12 :Ce0.5%. The dotted line is the Exc spectrum at 545nm Em. The lighter solid line is the Em spectrum at 457nm Exc, and the darker solid line is the Em spectrum at 322nm Exc.

[0119] Figure 4C is a graph showing the emission (Em) and excitation (Exc) spectra (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet of the presently disclosed subject matter: (Lu 1 / 3 Y 1 / 3 Tb 1 / 3 )3Al5O 12 :Ce0.5%. The dotted line is the Exc spectrum at 542nm Em. The lighter solid line is the Em spectrum at 448nm Exc, and the darker solid line is the Em spectrum at 320nm Exc.

[0120] Figure 4D is a graph showing the emission (Em) and excitation (Exc) spectra (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet of the presently disclosed subject matter: (Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce 0.5%. The dotted line is the Exc spectrum at 552nm Em. The lighter solid line is the Em spectrum at 456nm Exc, and the darker solid line is the Em spectrum at 335nm Exc.

[0121] Figure 4E is a graph showing the emission (Em) and excitation (Exc) spectra (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet of the presently disclosed subject matter: (Lu 1 / 5 Y 1 / 5 Dy 1 / 5 Tb 1 / 5 G1 / 5 )3Al5O 12 :Ce 0.5%. The dotted line is the Exc spectrum at 542nm Em. The lighter solid line is the Em spectrum at 453nm Exc, and the darker solid line is the Em spectrum at 338nm Exc.

[0122] Figure 5A is a graph showing the X-ray induced luminescence spectrum (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet crystal composition of the presently disclosed subject matter: (Y 1 / 3 Tb 1 / 3 G 1 / 3 )3Al5O 12 :Ce0.5%.

[0123] Figure 5B is a graph showing the X-ray luminescence spectrum (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet crystal composition of the presently disclosed subject matter: (Lu 1 / 3 Y 1 / 3 G 1 / 3 )3Al5O 12 :Ce0.5%.

[0124] Figure 5C is a graph showing the X-ray luminescence spectrum (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of an exemplary rare earth garnet crystal composition of the presently disclosed subject matter: (Lu 1 / 3 Y 1 / 3 Tb 1 / 3 )3Al5O 12 :Ce0.5%.

[0125] Figure 5D is a graph showing the X-ray stimulated luminescence spectrum (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of a crystal of an exemplary rare earth garnet composition of the presently disclosed subject matter: (Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce 0.5% (darker solid line) or 2% (lighter solid line).

[0126] Figure 5E is a graph showing X-ray stimulated luminescence spectra (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of crystals of two exemplary rare earth garnet compositions of the presently disclosed subject matter: (Lu 1 / 5 Y 1 / 5 Dy 1 / 5 Tb1 / 5Gd 1 / 5 )3Al5O 12 :Ce 0.5% (darker solid line) or 1% (lighter solid line).

[0127] Fig. 5F is a graph showing X-ray induced luminescence spectra (intensity in arbitrary units (au) and wavelength in nanometers (nm)) of particles of three exemplary rare earth garnet compositions of the presently disclosed subject matter: (Lu 1 / 3 Y 1 / 3 G 1 / 3 )3Al5O 12 :Ce (darker solid line), (Lu 1 / 4 Y 1 / 4 G 1 / 4 La 1 / 4 )3Al5O 12 :Ce (dashed line) and (Lu 1 / 3 Y 1 / 3 G 1 / 3 )3(Al 1 / 3Ga 1 / 3 Sc 1 / 3 )5O 12 :Ce (lighter solid line), all of these particles have 1% Ce.

[0128] Figure 6 is at 662keV( 137 Cs) excited multi-component (RE 1-x Ce x )3Al5O 12 Plot of the pulse height spectrum (counts vs. channel number) of a crystal. The spectrum shown by the light grey solid line is (Y 1 / 3 Tb 1 / 3 G 1 / 3 )3Al5O 12 :Ce 0.5%; the spectrum shown by the black solid line is (Lu 1 / 3 Y 1 / 3 G 1 / 3 )3Al5O 12 :Ce 0.5%; the spectrum shown by the black dashed line is (Lu 1 / 3 Y 1 / 3 Tb 1 / 3 )3Al5O 12 :Ce 0.5%; the spectrum shown by the solid gray line is (Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce 0.5%; and the spectrum shown by the gray dashed line is (Lu 1 / 4 Y1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce 2%.

[0129] Fig. 7A It is shown that the formula (Y 0.2 G 0.2 Tb 0.2 Yb 0.2 Lu 0.2 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0130] Figure 7B It is shown that the formula (Y 0.199 G 0.199 Tb 0.199 Yb 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0131] Figure 7C It is shown that the formula (Y 0.25 G 0.25 Er 0.25 Lu 0.25 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0132] Fig.7D It is shown that the formula (Y 0.24875 G 0.24875 Er 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0133] Fig. 7E It is shown that the formula (Y 0.25 G 0.25 Ho 0.25 Lu 0.25 )3Al5O 12A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0134] Figure 7F It is shown that the formula (Y 0.24875 G 0.24875 Ho 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 Graph of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0135] Figure 7G It is shown that the formula (Y 0.2 G 0.2 Tb 0.2 Dy 0.2 Lu 0.2 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0136] Figure 7H It is shown that the formula (Y 0.199 G 0.199 Tb 0.199 Dy 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0137] Fig.7I It is shown that the formula (Y 0.25 G 0.25 Tb 0.25 Lu 0.25 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0138] Figure 7J It is shown that the formula (Y 0.24875 G 0.24875 Tb 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0139] Figure 7K It is shown that the formula (Y 0.2 Eu 0.2 G 0.2 Yb 0.2 Lu 0.2 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0140] Figure 7L It is shown that the formula (Y 0.199 Eu 0.199 G 0.199 Yb 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0141] Figure 7M It is shown that the formula (Y 0.1667 Eu 0.1667 G 0.1667 Tb 0.1667 Yb 0.1667 Lu 0.1667 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0142] Figure 7N It is shown that the formula (Y 0.16583 Eu 0.16583 G 0.16583 Tb 0.16583 Yb 0.16583 Lu 0.16583 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0143] Fig.7O It is shown that the formula (Y 0.25 Sm 0.25 G 0.25Lu 0.25 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0144] Figure 7P It is shown that the formula (Y 0.24875 Sm 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0145] Figure 7Q It is shown that the formula (Y 0.25 Nd 0.25 G 0.25 Lu 0.25 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0146] Figure 7R It is shown that the formula (Y 0.24875 Nd 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0147] Figure 7S It is shown that the formula (Y 0.25 Pr 0.25 G 0.25 Lu 0.25 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0148] Figure 7T It is shown that the formula (Y 0.24875 Pr 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0149] Figure 7U It is shown that the formula (Y 0.25 La 0.25 G 0.25 Lu 0.25 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0150] Figure 7V It is shown that the formula (Y 0.24875 La 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0151] Figure 7W It is shown that the formula (Y 0.245 G 0.245 Tb 0.245 Lu 0.245 Ce 0.02 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0152] Figure 7X It is shown that the formula (Y 0.2375 G 0.2375 Tb 0.2375 Lu 0.2375 Ce 0.05 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0153] Figure 7Y It is shown that the formula (Y 0.163 G 0.163 Tb 0.49 Lu 0.163 Ce 0.02 )3Al5O 12A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0154] Figure 7Z It is shown that the formula (Y 0.294 G 0.294 Tb 0.098 Lu 0.294 Ce 0.02 )3Al5O 12 A graphical representation of a radioluminescence (RL) graph (intensity measured in arbitrary units (au), wavelength measured in nanometers (nm)) of a rare earth garnet composition of the presently disclosed subject matter.

[0155] Figure 8 is a schematic diagram of an apparatus for detecting radiation according to the presently disclosed subject matter. Apparatus 10 includes a photon detector 12 optically coupled to a scintillator material 14. Apparatus 10 may optionally include electronics 16 for recording and / or displaying electrical signals from photon detector 12. Thus, optional electronics 16 may be in electronic communication with photon detector 12. DETAILED DESCRIPTION

[0156] The presently disclosed subject matter will now be described more fully. However, the presently disclosed subject matter may be embodied in different forms and should not be construed as limited to the embodiments set forth below and in the accompanying drawings. Specifically, these embodiments are provided so that the present disclosure is thorough and complete and the scope of the embodiments is fully conveyed to those skilled in the art.

[0157] All references listed herein, including but not limited to all patents, patent applications and publications thereof, and scientific journal articles, are incorporated herein by reference in their entirety to the extent that they supplement, explain, provide context for, or teach the methods, techniques and / or components used herein.

[0158] I. Definition

[0159] While it is believed that the following terms are well understood by those of ordinary skill in the art, the following definitions are set forth to aid in explaining the presently disclosed subject matter.

[0160] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the presently disclosed subject matter belongs.

[0161] In accordance with long-standing patent law conventions, when used in this application, including the claims, the terms "a," "an," and "the" mean "one or more."

[0162] When used to describe two or more items or conditions, the term "and / or" means that all of the listed items or conditions are present or applicable or that only one (or not all) of the items or conditions are present or applicable.

[0163] Although the present disclosure supports definitions that only refer to alternatives and "and / or", the term "or" is used in the claims to mean "and / or" unless it is explicitly stated that only alternatives are referred to or the alternatives are mutually exclusive. As used herein, "another" can mean at least a second or more.

[0164] The term "comprising" is synonymous with "including", "containing" or "characterized by", and is inclusive or open-ended, but does not exclude additional, unrecited elements or method steps. "Comprising" is a technical term used in claim language to indicate that the listed elements are essential, but other elements may be added and still form a structure within the scope of the claim.

[0165] As used herein, the phrase "consisting of" excludes any element, step, or ingredient not specified in the claim. When the phrase "consisting of" appears in a clause in the body of a claim, rather than directly following the preamble, it is limited only to the elements stated in the clause; other elements are not excluded from the claim as a whole.

[0166] As used herein, the phrase "consisting essentially of limits the scope of a claim to the specified materials or steps, plus those that do not materially affect the basic and novel characteristics of the claimed subject matter.

[0167] With respect to the terms "comprising," "consisting of," and "consisting essentially of," where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms.

[0168] Unless otherwise indicated, all numbers expressing amounts of time, temperatures, light outputs, atomic (at) or molar (mol) percentages (%) and the like used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.

[0169] As used herein, the term "about" when expressing a value is intended to include variations of ±20% or ±10% in one instance, ±5% in another instance, ±1% in another instance, and ±0.1% in yet another instance of the stated amount, as such variations are suitable for performing the disclosed methods.

[0170] The term "scintillator" refers to a material that emits light (eg, visible light) in response to stimulation by high energy radiation (eg, X-, alpha, beta, or gamma radiation).

[0171] As used herein, the term "phosphor" refers to a material that emits light (e.g., visible light) in response to exposure to electromagnetic or particle radiation. Thus, a phosphor is a material that emits light (e.g., having a specific wavelength or wavelength range) when exposed to ultraviolet or visible light (e.g., a specific wavelength or wavelength range).

[0172] In some embodiments, the composition formula expression of the optical material (e.g., scintillating material or phosphor) may contain a colon ":" or a comma, wherein the left side of the colon or comma represents the main or basic host material (e.g., the main rare earth garnet host, i.e., RE3Al5O 12 ) and the activator (or dopant ion) is indicated to the right of the colon or comma. Alternatively, the composition formula expression may contain no colon, and the activator (or dopant), if present, may be included in the element it replaces, such as (RE / activator)3Al5O 12 middle.

[0173] The term "high-energy radiation" can refer to electromagnetic radiation having an energy higher than that of ultraviolet radiation, including but not limited to X-radiation (i.e., X-ray radiation), alpha particles, gamma radiation, and beta radiation. In some embodiments, high-energy radiation refers to gamma rays, cosmic rays, X-rays, and / or particles having an energy of 1 keV or greater. Scintillator materials as described herein can be used as components of radiation detectors in devices such as counters, image intensifiers, and computed tomography (CT) scanners.

[0174] As used herein, "optical coupling" refers to the physical coupling between the scintillator and the light sensor, for example, by the presence of an optical grease or another optical coupling compound (or refractive index matching compound) that bridges the gap between the scintillator and the light sensor. In addition to optical grease, the optical coupling compound can include, for example, liquids, oils, and gels.

[0175] "Light output" may refer to the number of photons produced per unit of energy deposited by, for example, absorbed gamma rays, typically in number of photons / MeV.

[0176] As used herein, chemical ions may be referred to simply by their individual chemical element symbols (e.g., Eu for europium ions (e.g., Eu 2+ ) or Sm represents a samarium ion (e.g., Sm 2+ )).

[0177] The term "rare earth element" as used herein refers to one or more elements selected from the lanthanide series (e.g., lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu)), scandium (Sc), and yttrium (Y).

[0178] As used herein, the term “transition metal element” refers to one or more elements selected from titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), mercury (Hg), ruthenium (Rf), niobium (Db), selenium (Sg), boron (Bh), hafnium (Hs), (Mt), (Ds), (Rg) and (Cn).

[0179] II. Multi-component rare earth garnet materials and related devices and methods

[0180] The presently disclosed subject matter provides multi-component rare earth garnet optical materials. These optical materials can be phosphors and / or scintillators. In some embodiments, the optical material comprises a general formula (RE 1-y X y )3(Al 1-z Ga z )5O 12The composition of or consisting of, wherein RE represents an ion of a combination of three or more rare earth elements (including Y and Sc). Therefore, the rare earth element can be selected from the group comprising Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La. X represents a luminescent activator, for example, Ce ions, Tb ions, Dy ions, Eu ions, Yb ions or Pr ions, and y is a relative activator concentration, and it is in the range of 0≤y≤0.1. Therefore, 0% to 10% of the total amount of rare earth element ions (RE) can be replaced by one or more activator ions. Although a small amount of X ions (for example, Ce, Tb, Dy, Eu, Yb or Pr ions) can be used as a luminescent activator, optically active matrix elements, for example, Yb, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd and Pr, which are usually present in a larger amount than the activator, can also contribute to luminescence. The relative concentration of Ga to Al in the garnet matrix (represented by the variable z) is in the range of 0≤z≤1. In addition, in some embodiments, some of the Al or Ga content may be replaced by rare earth ions (eg, Sc ions).

[0181] Optical material host matrix (ie, (RE)3(Al 1-z Ga z )5O 12 The concentration of rare earth elements in an optical material having no activator or co-doping ions) can be equimolar or non-equimolar in the melt or, alternatively, in the finished crystal or ceramic. In the case of stoichiometrically consistent molten compounds, in some embodiments, the concentration of rare earth elements is equimolar. For example, in a material having ions of four different rare earth elements, each ion can account for one quarter (i.e., 25%) of the total RE ions. For example, an exemplary formula with equimolar RE is (Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3Al5O 12 (It can also be expressed as (Lu 0.25 Y 0.25 Tb 0.25 G 0.25 )3Al5O 12 , i.e., when the relative amount of a particular RE ion in the formula is expressed as a percentage rather than a ratio).

[0182] In the case of non-uniform melt compounds, in some embodiments, the concentration of the rare earth element can be varied from equimolar to obtain consistency as needed. For example, an exemplary formula in which the rare earth element is non-equimolar is Y 3 / 8 Dy 1 / 8 Tb 1 / 4G 1 / 4 )3Al5O12 (It can also be expressed as (Y 0.375 Dy 0.125 Tb 0.25 G 0.25 )3Al5O 12 In some embodiments, the amount of activator ions X (relative to the total amount of RE ions), if present, such as Ce or Pr, in the optical material formula (i.e., (RE)3(Al 1-z Ga z )5O 12 :X y%) is provided as a percentage (i.e., atomic percentage) after a colon, as in the above general formula (i.e., (RE 1-y X y )3(Al 1-z Ga z )5O 12 ) wherein the relative amount of the activator ion X as a ratio or percentage is contained within parentheses that also describe the combination of the rare earth element ion RE.

[0183] In the case of large variations in rare earth element ion radius, the concentration of rare earth elements with different ionic radii can be adjusted to stabilize the cubic garnet phase or achieve consistent melting, taking into account the segregation at the solid-liquid interface. Examples of these include, but are not limited to (Lu 1 / 4 Y 1 / 4 Tb 1 / 4 G 1 / 4 )3(Al 1 / 2 Ga 1 / 2 )5O 12 :Ce、(Y 3 / 8 Dy 1 / 8 Tb 1 / 4 G 1 / 4 )3Al5O 12 :Ce and (Lu 1 / 9 Y 1 / 9Tb 2 / 9 G 2 / 9 Sm 3 / 9 )3Al5O 12 :Ce.

[0184] In some embodiments, for example, when doped with an activator such as trivalent Ce or Pr, the presently disclosed optical materials become scintillators suitable for radiation detection applications including medical imaging, homeland security, and high energy physics experiments.

[0185] Thus, in some embodiments, the presently disclosed subject matter provides an optical material comprising or consisting of a component of the formula:

[0186] (RE 1-y X y)3(Al 1-z Ga z )5O 12 ,

[0187] Wherein: 0≤y≤0.1; 0≤z≤1; RE is a combination of ions of three or more rare earth elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La; and X is one or more activator ions selected from the group consisting of Ce ions, Tb ions, Dy ions, Eu ions, Yb ions and Pr ions. As described above, the relative concentration of each rare earth element ion in the optical material can be approximately the same (i.e., equimolar) or can be different.

[0188] In some embodiments, z is 0. Thus, in some embodiments, the optical material does not contain any Ga, and the optical material comprises the formula (RE 1-y X y )3Al5O 12 or consist of.

[0189] In some embodiments, RE is a combination of ions of three, four, five or six elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La. In some embodiments, RE is a combination of ions of at least three elements selected from Y, Lu, Tb and Gd. In some embodiments, RE comprises Y ions. In some embodiments, RE comprises Lu ions.

[0190] In some embodiments, y is 0 (and the optical material does not include an activator ion X). For example, in some embodiments, the optical material comprises or consists of a component selected from the group consisting of: (Y 0.2 G 0.2 Tb 0.2 Y 0.2 Lu 0.2 )3Al5O 12 ;(Y 0.25 G 0.25 Er 0.25 Lu 0.25 )3Al5O 12 ;(Y 0.25 G 0.25 Ho 0.25 Lu 0.25 )3Al5O 12 ;(Y 0.2 G 0.2 Tb 0.2 Dy 0.2 Lu 0.2 )3Al5O12 ;(Y 0.25 G 0.25 Tb 0.25 Lu 0.25 )3Al5O 12 ;(Y 0.2 Eu 0.2 G 0.2 Yb 0.2 Lu 0.2 )3Al5O 12 ;(Y 0.1667 Eu 0.1667 G 0.1667 Tb 0.1667 Yb 0.1667 Lu 0.1667 )3Al5O 12 ;(Y 0.25 G 0.25 Tb 0.25 Lu 0.25 )3Al5O 12 ;(Y 0.25 Nd 0.25 G 0.25 Lu 0.25 )3Al5O 12 ;(Y 0.25 Pr 0.25 G 0.25 Lu 0.25 )3Al5O 12 ; and (Y 0.25 La 0.25 G 0.25 Lu 0.25 )3Al5O 12 .

[0191] In some embodiments, the optical material comprises at least a certain amount of one or more activator ions. In some embodiments, 0.001≤y≤0.1 (i.e., the optical material comprises 0.1% activator (i.e., 0.1 at% activator ions relative to the total amount of RE ions) to 10% activator). In some embodiments, 0.005≤y≤0.05 (e.g., 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, or 0.050). In some embodiments, y is 0.005, 0.02, or 0.05. In some embodiments, X is Ce ions, Pr ions, or Tb ions. In some embodiments, X is Ce ions, Pr ions, or mixtures thereof. In some embodiments, X is Ce 3+ .

[0192] In some embodiments, the optical material comprises or consists of a component selected from the group consisting of:

[0193] (Y 0.199 G 0.199 Tb 0.199 Yb 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 ;

[0194] (Y 0.24875 G 0.24875 Er 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0195] (Y 0.24875 G 0.24875 Ho 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0196] (Y 0.199 G 0.199 Tb 0.199 Dy 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 ;

[0197] (Y 0.24875 G 0.24875 Tb 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0198] (Y 0.199 Eu 0.199 G 0.199 Yb 0.199 Lu 0.199 Ce 0.005 )3Al5O 12 ;

[0199] (Y 0.16583 Eu 0.16583 G 0.16583 Tb 0.16583 Yb 0.16583 Lu 0.16583 Ce 0.005 )3Al5O 12 ;

[0200] (Y 0.24875 Sm0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0201] (Y 0.24875 Nd 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0202] (Y 0.24875 Pr 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0203] (Y 0.24875 La 0.24875 G 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ;

[0204] (Y 0.245 G 0.245 Tb 0.245 Lu 0.245 Ce 0.02 )3Al5O 12 ;

[0205] (Y 0.2375 G 0.2375 Tb 0.2375 Lu 0.2375 Ce 0.05 )3Al5O 12 ;

[0206] (Y 0.2375 G 0.2375 Tb 0.2375 Lu 0.2375 Ce 0.05 )3Al5O 12 ;and

[0207] (Y 0.294 G 0.294 Tb 0.098 Lu 0.294 Ce 0.02 )3Al5O 12 .

[0208] In some embodiments, the optical material comprises or consists of a component selected from the group consisting of:

[0209] (Y 0.33167 Tb 0.33167 G 0.33167 Ce 0.005 )3Al5O 12 ;

[0210] (Lu 0.33167 Y 0.33167 G 0.33167 Ce 0.005 )3Al5O 12 ;

[0211] (Lu 0.33167 Y 0.33167 Tb 0.33167 Ce 0.005 )3Al5O 12 ;

[0212] (Lu 0.24875 Y 0.24875 Tb 0.24875 G 0.24875 Ce 0.005 )3Al5O 12 ;and

[0213] (Lu 0.245 Y 0.245 Tb 0.245 G 0.245 Ce 0.02 )3Al5O 12 .

[0214] In some embodiments, the optical material provides light emission from photoactive RE ions when the optical material is stimulated with high-energy radiation. In some embodiments, the photoactive RE ions are Dy ions, Er ions, Sm ions, Eu ions, Yb ions, Tb ions, or Pr ions, or any combination of any of the foregoing ions. In some embodiments, the photoactive RE ions are Tb ions or Pr ions. In some embodiments, the photoactive RE ions are Tb ions. In some embodiments, the optical material comprises photoactive RE ions, such as Tb ions, as one of the RE ions, and further comprises another ion as an activator ion, such as Ce ions, Dy ions, Eu ions, Yb ions, or Pr ions. Alternatively, in some embodiments, Tb is used as an activator ion (e.g., the relative at% of Tb is 10 atomic% or less compared to other RE ions), and the optical material comprises ions of at least three other RE elements.

[0215] The optical material may be provided as a single crystal, polycrystalline material, powder (eg, green powder), or ceramic.

[0216] III. Radiation detectors, related devices and methods

[0217] In some embodiments, the presently disclosed subject matter provides a radiation detector comprising an optical material as described above or a mixture of such materials. For example, the radiation detector may comprise an optical material that is capable of acting as a scintillator (which absorbs radiation and emits light) and a photodetector (which detects the luminescence). The photodetector may be any one or more suitable detectors and may or may not be optically coupled to the optical material for generating an electrical signal in response to light emission from the optical material. Thus, the photodetector may be configured to convert photons into electrical signals. For example, a signal amplifier may be provided to convert the output signal of a photodiode into a voltage signal. The signal amplifier may also be designed to amplify the voltage signal. Electronic devices associated with the photodetector may be used to shape and digitize the electrical signal.

[0218] Now refer to Figure 8 In some embodiments, the presently disclosed subject matter provides a device 10 for detecting radiation, wherein the device includes a photon detector 12 and a scintillator material 14 (i.e., a rare earth garnet optical material used as a scintillator). The scintillator material 14 can convert radiation into light that can be efficiently and quickly collected by a charge coupled device (CCD) or a photomultiplier tube (PMT) or other photon detector 12.

[0219] Refer again Figure 8 The photon detector 12 can be any one or more suitable detectors and can be optically coupled (e.g., by optical grease or another optical coupling compound, such as optical coupling oil or liquid) to the scintillator for generating an electrical signal in response to light emission from the scintillator. Thus, the photodetector 12 can be configured to convert photons into electrical signals. Electronic devices associated with the photon detector 12 can be used to shape and digitize the electrical signals. Suitable photon detectors 12 include, but are not limited to, photomultiplier tubes, photodiodes, CCD sensors, and image intensifiers. The device 10 may also include electronic devices 16 for recording and / or displaying the electrical signals.

[0220] In some embodiments, the radiation detector is configured to be used as a part of a medical or veterinary diagnostic device, a device for oil or other geological exploration (e.g., an oil logging probe), or a device for security and / or military-related purposes (e.g., used as a device for container, vehicle, or luggage scanning or for scanning humans or other animals). In some embodiments, the medical or veterinary diagnostic device is selected from, but not limited to, a positron emission tomography (PET) device, an X-ray computed tomography (CT) device, a radiographic imaging device, a single photon emission computed tomography (SPECT) device, or a planar nuclear medicine imaging device. For example, the radiation detector can be configured to move (e.g., by mechanical and / or electronic control) on and / or around a sample (such as a human or animal subject) so that radiation emitted from any one or more desired locations on the sample can be detected. In some embodiments, the detector can be set or mounted on a rotating body to rotate the detector around the sample. In some embodiments, the radiation detector is configured for use in CT, radiographic imaging, or high energy physics research.

[0221] In some embodiments, the device may also include a radiation source. For example, the X-ray CT device of the presently disclosed subject matter may include an X-ray source for radiating X-rays and a detector for detecting the X-rays. In some embodiments, the device may include a plurality of radiation detectors. The plurality of radiation detectors may be arranged in, for example, a cylindrical or other desired shape to detect radiation emitted from different positions on the surface of the sample.

[0222] In some embodiments, the presently disclosed subject matter provides a method of detecting radiation (or the absence of radiation) using a radiation detector comprising a rare earth garnet optical material as described above (i.e., a scintillator material comprising a rare earth garnet optical material). Thus, in some embodiments, the presently disclosed subject matter provides a method of detecting gamma rays, X-rays, cosmic rays, and / or particles having an energy of 1 keV or greater, wherein the method comprises using a radiation detector comprising a rare earth garnet optical material as disclosed herein or a mixture of such materials. In some embodiments, the method comprises using a radiation detector in computed tomography, radiographic imaging, or high energy physics research.

[0223] In some embodiments, the method may include providing a radiation detector comprising a photodetector and a rare earth garnet optical material of the presently disclosed subject matter; arranging the detector, wherein the arranging includes placing the detector in a position where the optical material is in a path of a radiation beam (or a suspected path of a radiation beam); and detecting light emitted by the optical material (or the absence of light) with the photodetector. Detecting light emitted by the optical material may include converting photons into electrical signals. Detecting may also include processing the electrical signal to shape, digitize, or amplify the signal. The method may also include displaying the electrical signal or the processed electrical signal.

[0224] In some embodiments, the presently disclosed subject matter provides a use of a radiation detector comprising a photon detector and a scintillator material comprising a rare earth garnet optical material as described above. In some embodiments, the use is for medical or veterinary diagnosis (e.g., the radiation detector is configured for use in medical or veterinary diagnosis). In some embodiments, the use is in computed tomography, radiographic imaging, or high energy physics research.

[0225] IV. Preparation method of optical materials

[0226] The presently disclosed materials can be prepared by any suitable route, such as but not limited to a crystal synthesis route, a powder synthesis route, or a ceramic synthesis route. Representative, non-limiting examples of such routes are disclosed in the following examples, and it will be apparent to one of ordinary skill in the art upon reading this disclosure that other examples of such routes and other synthesis routes also fall within the scope of the presently disclosed subject matter.

[0227] For example, in some embodiments, suitable reactants (e.g., metal nitrates or metal oxides, such as Lu2O3, CeO2, Pr6O3, α-Al2O3, Ga2O3, Gd2O3, etc.) are melted at a temperature sufficient to form a consistent molten composition. The melting temperature may depend on the characteristics of the reactants themselves (e.g., on the melting points of the individual reactants), but is generally in the range of about 300°C to about 1350°C. Exemplary techniques for preparing materials include, but are not limited to, Bridgman or Bridgman-Stockbarger methods, Czochralski methods, zone melting methods (or "floating zone" methods), vertical gradient freezing (VGF) methods, and temperature gradient methods.

[0228] For example, in some embodiments, high purity reactants can be mixed and melted to synthesize a compound having a desired composition. Single or polycrystalline materials can be grown from the synthesized compound by the Bridgman method, wherein a sealed ampoule containing the synthesized compound is transferred from a hot zone to a cold zone at a controlled rate (i.e., a "stretch rate") through a controlled temperature gradient. In some embodiments, high purity reactants can be mixed in a stoichiometric ratio, which depends on the desired composition of the scintillator material, and then loaded into an ampoule, which is then sealed. After sealing, the ampoule is heated and then cooled at a controlled rate. In some embodiments, the optical material (e.g., scintillator material) of the presently disclosed subject matter is prepared by a vertical Bridgman technique. In some embodiments, the stretching (or translation) rate used when preparing the scintillator crystal by the Bridgman technique is about 0.1 millimeter / hour (mm / hr) to about 5 mm / hr (e.g., about 0.1 mm / hr; about 0.5 mm / hr, about 1 mm / hr, about 2 mm / hr, about 3 mm / hr, about 4 mm / hr, or about 5 mm / hr). In some embodiments, the method includes using a stretching rate of about 3 mm / hr.

[0229] In some embodiments, the presently disclosed subject matter provides a method for preparing a rare earth garnet (RE) 3 (AlGa) 5 O 12 A method for preparing an optical material wherein RE is a mixture of ions of at least three rare earth elements, optionally wherein up to about 10 atomic % of the RE ions are replaced by one or more activator ions of an element selected from Ce, Tb, Dy, Eu, Yb, and Pr. In some embodiments, the method comprises heating a mixture of raw materials (e.g., a mixture of metal oxides in stoichiometric ratios, depending on the formula of the desired optical material) to a temperature above their respective melting temperatures (i.e., above the melting temperature of the raw material with the highest melting temperature). In some embodiments, the raw materials are dried before, during, or after mixing. In some embodiments, the raw materials are mixed under low humidity and / or low oxygen conditions. In some embodiments, the raw materials are mixed in a dry box and / or under conditions of less than about 0.1 parts per million (ppm) of moisture and / or oxygen (e.g., less than about 0.1 ppm, less than about 0.09 ppm, less than about 0.08 ppm, less than about 0.07 ppm, less than about 0.06 ppm, less than about 0.05 ppm, less than about 0.04 ppm, less than about 0.03 ppm, less than about 0.02 ppm, or less than about 0.01 ppm of moisture and / or oxygen).

[0230] The mixture of raw materials can be sealed in a container (e.g., quartz ampoule) that can withstand the subsequent heating of the mixture and is chemically inert for the mixture of raw materials. The mixture can be heated to a temperature higher than the melting temperature of each raw material at a predetermined rate. In some embodiments, the mixture can be heated to a temperature higher than the melting temperature of the raw material with the highest melting temperature by about 10°C to about 50°C (e.g., about 10°C, about 12°C, about 14°C, about 16°C, about 18°C, about 20°C, about 22°C, about 24°C, about 26°C, about 28°C, about 30°C, about 32°C, about 34°C, about 36°C, about 38°C, about 40°C, about 42°C, about 44°C, about 46°C, about 48°C or 50°C). In some embodiments, the mixture is heated to a melting temperature of about 50°C higher than the raw material with the highest melting temperature. This temperature can be maintained for a period of time, such as about 2 to about 36 hours (e.g., about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 14, about 16, about 18, about 20, about 22, about 24, about 26, about 28, about 30, about 32, about 34 or about 36 hours). In some embodiments, the temperature is maintained for about 24 hours. The mixture can then be cooled at a predetermined rate until the mixture reaches about room temperature (e.g., about 20°C to about 25°C). As needed, the sealed container can be rotated or flipped. In some embodiments, heating and cooling can be repeated, for example, to provide further mixing of all components in the mixture. As needed, rotation or flipping and heating / cooling steps can be repeated one or more times.

[0231] In some embodiments, the method further comprises a post-growth annealing step. Thus, in some embodiments, the method further comprises annealing the optical material (e.g., a crystalline optical material). The annealing can be carried out in, for example, air, nitrogen, or a mixture of nitrogen and hydrogen. The annealing can be carried out at any suitable temperature below the melting point of the optical material, for example, at about 100°C to about 1600°C (e.g., about 100°C, about 200°C, about 300°C, about 400°C, about 500°C, about 600°C, about 700°C, about 800°C, about 900°C, about 1000°C, about 1100°C, about 1200°C, about 1300°C, about 1400°C, about 1500°C, and about 1600°C).

[0232] In some embodiments, the optical (e.g., scintillating) material can be provided as a single crystal, a polycrystalline material, and / or a ceramic material. In some embodiments, the material is provided as a polycrystalline material. The polycrystalline material can have similar physical, optical, and scintillating properties to a single crystal having otherwise the same chemical composition.

[0233] In some embodiments, the presently disclosed subject matter provides a method of preparing an optical material of the presently disclosed subject matter, that is, the optical material comprises or consists of a component of the formula:

[0234] (RE 1-y X y )3(Al 1-z Ga z )5O 12 ,

[0235] wherein: 0≤y≤0.1; 0≤z≤1; RE is a combination of ions of three or more rare earth elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La; and X is one or more activator ions selected from the group consisting of Ce ions, Tb ions, Dy ions, Eu ions, Yb ions and Pr ions, wherein the method comprises:

[0236] (a) preparing a single crystal of an optical material from a melt (e.g., as described above);

[0237] (b) preparing a powder of an optical material by: (i) preparing a foam by heating an aqueous solution comprising a mixture of a polymer (polyvinyl alcohol (PVA) or polyethylene glycol (PEG)) and a metal nitrate, wherein the metal nitrate comprises an element ion corresponding to the element of the optical material, and pulverizing the foam to provide a powder; or (ii) co-precipitating a powder by adding an aqueous solution comprising a mixture of a metal nitrate and ammonium sulfate to an aqueous ammonium carbonate solution, wherein the metal nitrate comprises an element ion corresponding to the element of the optical material; or

[0238] (c) preparing a ceramic of an optical material (eg, using binary oxides as starting materials) by a technique selected from the group consisting of sintering, hot pressing, hot isostatic pressing and spark plasma synthesis.

[0239] Thus, in some embodiments, the optical material is provided as a powder (e.g., a green powder). In some embodiments, the powder can be prepared by preparing a foam and then crushing the foam (e.g., dehydrating the foam) to provide a powder. For example, in some embodiments, the foam can be prepared by heating an aqueous solution containing a mixture of a polymer and a metal nitrate, the metal nitrate containing element ions corresponding to the elements in the desired optical material. In some embodiments, the polymer is PVA or PEG. In some embodiments, the polymer is PVA. In some embodiments, preparing the foam further includes heating the aqueous solution to evaporate water from the aqueous solution. In some embodiments, the foam can be further dehydrated in an oven for a period of time to remove residual moisture. In some embodiments, the foam can be placed in an oven at about 180°C for about 2 hours. In some embodiments, the method also includes calcining the powder in air (e.g., calcining at about 650°C for about 2.5 hours) to remove nitrates and polymers (e.g., PVA). In some embodiments, the powder can be crystallized. Crystallization can be carried out in air at a temperature of about 900°C to about 1300°C for a period of time (e.g., about 1 hour).

[0240] Alternatively, the powder can be prepared by coprecipitation. For example, in some embodiments, the method includes coprecipitating the powder by adding an aqueous solution containing a mixture of metal nitrates and ammonium sulfate to an aqueous ammonium carbonate solution, wherein the metal nitrate contains elemental ions corresponding to the element of the optical material. The precipitate that falls off the solution can be collected by filtration. As with the powder prepared by foaming, in some embodiments, the initially precipitated powder can be calcined. In some embodiments, the powder can be crystallized (e.g., in air at a temperature of about 900° C. to about 1300° C.).

[0241] In some embodiments, a mixture of metal oxides including metal elements corresponding to desired rare earth garnets may be mixed and ground in a mortar and then pressed into granules.

[0242] In some embodiments, the presently disclosed subject matter provides a method of preparing a ceramic of an optical material as described herein, wherein the method comprises performing a technique selected from the group consisting of hot pressing, hot isostatic pressing, and spark plasma synthesis. In some embodiments, the method comprises using a binary oxide as a starting material for the ceramic. For example, in some embodiments, annealing can include grinding a stoichiometric mixture of binary oxides, pressing the mixture to form particles, and annealing the particles at a temperature of about 1500°C for a period of time (e.g., about 10 hours). In some embodiments, a stoichiometric mixture of binary oxide powders or rare earth garnet powders can be hot pressed at a temperature of about 1000°C to about 2000°C at about 5 MPa to about 100 MPa for a period of time (e.g., about 2 hours).

[0243] Example

[0244] The following examples are included to further illustrate various embodiments of the disclosed subject matter. However, based on this disclosure, those of ordinary skill in the art will appreciate that many changes can be made in the specific embodiments disclosed without departing from the spirit and scope of the disclosed subject matter and still obtain similar or similar results.

[0245] Example 1

[0246] powder synthesis

[0247] Polymer synthesis route:

[0248] The metal nitrates were dissolved in a beaker of deionized (DI) water, and polyvinyl alcohol (PVA, 9k-10kg / mol, 80% hydrolyzed) was dissolved in another beaker of DI water. After the two solutions were dissolved, they were mixed and heated on an electric stove to evaporate the water to produce foam. The foam was placed in an oven at 180°C for 2 hours to remove residual moisture. The powder produced by crushing the dehydrated foam was calcined in air at 650°C for 2.5 hours to remove the nitrates and PVA. The resulting powder was crystallized in air at a temperature of 900-1300°C for 1 hour. The result is a multi-component rare earth garnet powder.

[0249] Co-precipitation route:

[0250] The metal nitrates and ammonium sulfate were dissolved in a beaker of deionized water, and ammonium carbonate was dissolved in a separate beaker of deionized water. The nitrate solution was added dropwise to the carbonate solution to form a precipitate. The precipitate was filtered from the combined solution and calcined in air at 650°C for 2.5 hours. The resulting powder was crystallized in air at a temperature of 900-1300°C for 1 hour. The result was a multi-component rare earth garnet powder.

[0251] Example 2

[0252] Synthesis of ceramics

[0253] The ceramic can be prepared from the multicomponent rare earth garnet powder prepared in Example 1 or from binary oxide powders having a purity of at least 99.99%, which are dried in air at 800°C for 5 hours.

[0254] annealing:

[0255] The stoichiometric mixture of dry powders was ground in an agate mortar and pressed into pellets with a diameter of 13 mm. The pellets were sintered at 1500°C for 10 hours in air.

[0256] Heat Pressing:

[0257] The stoichiometric binary oxide powder or multi-component rare earth garnet powder is pressed into particles with a diameter of 13 mm. The obtained green particles are hot pressed at a temperature of 1400-1500° C. and 5-10 MPa for 2 hours.

[0258] Example 3

[0259] Synthesis of single crystals

[0260] The stoichiometric mixture of the dry powders was mixed by hand stirring in a 4 ml glass bottle. Cylindrical single crystals with a diameter of 3 mm were grown using a KDN Dai-Ichi Kiden micro-pull-down furnace (Dai-Ichi Kiden Co., Ltd., Tokyo, Japan) equipped with a TR-02001 radio frequency (RF) generator operating at 26 kilovolt-amperes (kVA). Iridium crucible (with Mold and The capillary channel is used as a melt reservoir. 12 The seed crystal contacts the outlet of the capillary channel to initiate growth. The RF generator power is gradually increased over 2 hours to reach the melting point, which is visually determined by probing the capillary with a seed crystal and observing the presence of molten material. A charge coupled device (CCD) camera is focused on the bottom of the crucible mold to enable real-time visualization of inoculation and monitoring of the molten zone. The stretching rate used is in the range of 0.05-0.20 mm / min. After growth is completed, the RF generator power is gradually reduced over four hours. The resulting single crystal has good optical quality. Disks with a thickness of 1 mm are cut and polished for optical and scintillation characterization.

[0261] Example 4

[0262] Characterization of rare earth garnet optical materials

[0263] Photographs of crystals, ceramics, and green materials of the disclosed subject matter are shown in Figure 1 and Figure 2 shown.

[0264] Specific examples of single crystals include, but are not limited to, the crystals reported in Table 1 below.

[0265] Table 1. Multicomponent (RE 1-x Ce x )3Al5O 12 Flash performance

[0266]

[0267] Structural performance

[0268] Despite the complex multi-component composition, powder X-ray diffraction (XRD) revealed a single cubic garnet structure with space group Ia-3d. (RE 1-x Ce x )3Al5O 12 Examples of powder XRD patterns of crystals are Figure 3 Without being bound by any one theory, since these single crystals were grown from a melt, it is believed that the compounds melted uniformly. Furthermore, there was no indication of a phase transition from the crystallization temperature to room temperature.

[0269] Optical and scintillation performance

[0270] Photoluminescence (PL) spectra were acquired at room temperature using a Hitachi fluorescence spectrophotometer (Hitachi, Tokyo, Japan) equipped with a xenon lamp. Figures 4A-4E The spectra shown are characteristic of trivalent Ce luminescence, which involves 4f-5d transitions and is found in both single-component and double-component (RE 1-x Ce x )3Al5O 12 This transition has also been observed in the PL spectra of Ce[2-9]. These PL spectra include a maximum in the range of 542-552nm. 3+ The emission band corresponds to Ce 3+ The excitation bands of 4f-5d1 and 4f-5d2 transitions have maxima in the range of 448-457nm and 335-341nm, respectively. In addition, compounds containing Tb have absorption bands around 375nm and below 300nm, corresponding to Tb 3+ 4f-4f transition. In the three-component composition containing Tb (see Figure 4B and 4C ), Ce 3+ 4f-5d2 and Tb 3+ The 4f-4f excitation bands overlap, with maxima around 320nm. The emission spectra monitored at these excitation maxima have characteristic Ce 3+ emission band, which is closely related to the sharp Tb 3+ The 4f-4f emission peaks overlap.

[0271] The radioluminescence (RL) spectra were measured at room temperature under continuous irradiation with a CMX003 X-ray generator (32 kV and 0.1 mA). The spectra were recorded using a monochromator sold by Telecyne Digital Imaging US Inc., Thousand Oaks, CA, USA. Figures 5A-5F The most intense emission band in the radiative luminescence spectrum shown is Ce 3+Emission band, maximum in the range of 535-563nm. Compounds containing Tb (see Figure 5A and 5C -5E) also has Tb near 495, 582, 625 and 652nm 3+ Emission characteristics.

[0272] The absolute light output of the crystal sample is obtained by measuring the pulse height spectrum, e.g. Figure 6 A Hamamatsu 3177-50 photomultiplier tube (PMT) (Hamamatsu Photonics KK, Shizuoka, Japan) was used. The sample was directly coupled to the PMT using optical grease and covered with multiple layers of polytetrafluoroethylene (PTFE) tape (trade name A reflector made from a polymer sold under the trade name SPECTRALON (Labsphere, Inc., North Sutton, New Hampshire, USA) was placed on top of the tape. 137 The gamma-ray energy spectrum was recorded by a Cs excitation source. Based on the emission spectrum of the crystal, the integrated quantum efficiency of the PMT was used to estimate the photon light output per unit gamma-ray energy, as shown in Table 1.

[0273] Other Ingredients

[0274] The data in Table 2 were collected from green particles of other exemplary rare earth garnets. The RL spectra measured for both Ce-doped and undoped compositions show scintillation emission. Figures 7A-7Z . The powder XRD data provided were used to identify the formation of the garnet phase. Rietveld refinement of the powder XRD data was used to extract the lattice parameters, which were then used to calculate the density of the garnet phase. The nominal composition was assumed for the density calculation, which is a suitable assumption for pure sample phases. However, it can be noted that for samples containing secondary phases, the nominal composition cannot constitute the garnet phase, which may lead to errors in the density calculation. Table 2 below summarizes the RL and XRD patterns of other exemplary rare earth garnets.

[0275] Table 2. Radioluminescence and structural properties of green particles.

[0276]

[0277]

[0278] References

[0279] All references listed herein, including but not limited to all patents, patent applications and publications thereof, scientific journal articles, and database entries, are incorporated herein by reference in their entirety, to the extent that they supplement, explain, provide context or teach the methods, techniques and / or ingredients employed herein.

[0280] [1]Euler, F.; Bruce, JA, Oxygen Coordinates of Compounds with GarnetStructure. Acta Crystallogr 1965,19,971-978.

[0281] [2]Nikl, M.; Yoshikawa, A.; Kamada, K.; Nejezchleb, K.; Stanek, CR; Mares, JA; Blazek, K., Development of LuAG-based scintillator crystals-A review. ProgCryst Growth Ch 2013, 59(2), 47-72.

[0282] [3]Su,

[0283] [4] Li, J.; Li, JG; Liu, S.; Li, X.; Sun,

[0284] [5]Hu,S.;Qin,X.;Zhou,G.;Lu,C.;Guanghui,L.;Xu,Z.;Wang,Z.,Luminescencecharacteristics of the Ce3+-doped garnets:the case of Gd-admixed Y3Al5O12transparent ceramics.Opt.Mater.Express 2015 5 12.

[0285] [6]Shao,C.;Zhang,L.;Zhou,T.;Gu,L.;Sun,B.;Jiang,Z.;Yao,Q.;Bu,W.;Wang,K.;Chen,H.,Gd2O3 assisted densification of high quantity(Y,Gd)AG:Ce ceramicsolidsolutions and their luminescencecharacteristics.Ceram.Int.2018 44 8672-8678.

[0286] [7]Boukerika,A.;Guerbous,L.;Belamri,M.,Effect of Y3+substitution onstructural and photoluminescence properties of solid solutions[(Lu1xYx)1zCez]3Al5O12 phosphors.Mater.Chem.Phys.2016 171 394-399.

[0287] [8]Yadav,S.K.;Uberuaga,B.P.;Nikl,M.;Jianng,C.;Stanek,C.R.,Band-Gapand Band-Edge Engineering of Multicomponent Garnet Scintillators from FirstPrinciples.Phys.Rev.Applied.2015 4 054012.

[0288] [9]Dorenbos, P., Electronic structure and optical properties of thelanthanide activated RE3(Al1-xGax)5O12(RE=Gd,Y,Lu)garnet compounds.Journalof Luminescence.2013 134 310-318.

[0289] It should be understood that various details of the disclosed subject matter can be changed without departing from the scope of the presently disclosed subject matter.In addition, the above description is for illustrative purposes only, not for limiting purposes.

Claims

1. An optical material comprising a composition of the following formula: (RE 1-y X y )3(Al 1-z Ga z )5O 12 , in: 0≤y≤0.1； 0≤z≤1； RE is a combination of ions of three or more rare earth elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La; and X is one or more activator ions selected from the group consisting of Ce ions, Tb ions, Dy ions, Eu ions, Yb ions, and Pr ions.

2. The optical material according to claim 1, wherein z is 0.

3. An optical material according to claim 1 or claim 2, wherein RE is a combination of ions of three, four, five or six elements selected from the group consisting of Y, Sc, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr and La.

4. The optical material according to any one of claims 1 to 3, wherein RE is a combination of ions of at least three elements selected from the group consisting of Y, Lu, Tb and Gd.

5. The optical material according to any one of claims 1 to 4, wherein y is 0.

6. The optical material according to any one of claims 1 to 4, wherein 0.001≤y≤0.

1.

7. The optical material of claim 6, wherein 0.005≤y≤0.05; optionally wherein y is 0.005, 0.02 or 0.

05.

8. The optical material according to claim 6, wherein X is Ce ion, Pr ion or a mixture thereof, optionally wherein X is Ce 3+ .

9. The optical material of claim 1, wherein the optical material comprises a component selected from the group consisting of: (AND 0.2 Gd 0.2 Tb 0.2 AND 0.2 Lu 0.2 )3Al5O 12 ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Er<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Ho<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> Dy<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Y 0.2 I 0.2 Gd 0.2 Yb 0.2 Read 0.2 )3Al5O 12 ; (Y 0.1667 I 0.1667 Gd 0.1667 Tb 0.1667 Yb 0.1667 Read 0.1667 )3Al5O 12 ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Nd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Y 0.25 Pr 0.25 Gd 0.25 Lu 0.25 )3AlO 12 ;sum <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> No<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.25 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> 。 10. The optical material of claim 1, wherein the optical material comprises a component selected from the group consisting of: <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Yb<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Y 0.24875 G 0.24875 Er 0.24875 Lu 0.24875 Ce 0.005 )3Al5O 12 ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ho<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Dy<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.199 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Y 0.199 I 0.199 Gd 0.199 Yb 0.199 Read 0.199 This 0.005 )3Al5O 12 ; (Y 0.16583 I 0.16583 Gd 0.16583 Tb 0.16583 Yb 0.16583 Read 0.16583 This 0.005 )3Al5O 12 ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Sm<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Nd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Pr<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> No<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.24875 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.02 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.2375 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.2375 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.2375 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.2375 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.05 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Y 0.2375 G 0.2375 Tb 0.2375 Lu 0.2375 Ce 0.05 )3Al5O 12 ;and <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.294 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.294 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.098 <h2 style=";text-align:left;direction:ltr"> Lu<h2 style=";text-align:left;direction:ltr"> 0.294 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.02 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> 。 11. The optical material of claim 1, wherein the optical material comprises a component selected from the group consisting of: <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Lu<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Lu<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Lu 0.24875 Y 0.24875 Tb 0.24875 G 0.24875 Ce 0.005 )3Al5O 12 ;and <h2 style=";text-align:left;direction:ltr">(Lu<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.02 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> 。 12. The optical material of any one of claims 1-11, wherein the optical material provides light emission from photoactive RE ions upon stimulation of the optical material with high energy radiation, optionally wherein the photoactive RE ions are Tb ions.

13. A radiation detector comprising the optical material of any one of claims 1 to 12 and a photon detector, optionally wherein the optical material is an optical material selected from the group consisting of: <h2 style=";text-align:left;direction:ltr">(Y<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Lu<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; <h2 style=";text-align:left;direction:ltr">(Lu<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.33167 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.005 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> ; (Lu 0.24875 Y 0.24875 Tb 0.24875 G 0.24875 Ce 0.005 )3Al5O 12 ;and <h2 style=";text-align:left;direction:ltr">(Lu<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Tb<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Gd<h2 style=";text-align:left;direction:ltr"> 0.245 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.02 <h2 style=";text-align:left;direction:ltr"> )3Al5O<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> 。 14. A method of detecting gamma rays, X-rays, cosmic rays and / or particles having an energy of 1 keV or greater, the method comprising using the radiation detector of claim 13.

15. Use of the radiation detector of claim 13 in medical imaging, homeland security, or high energy physics research.

16. A method for preparing the optical material according to any one of claims 1 to 12, wherein the method comprises preparing a single crystal of the optical material from a melt.

17. A method for preparing the optical material according to any one of claims 1 to 12, wherein the method comprises preparing a powder of the optical material by the following steps: (i) preparing a foam by heating an aqueous solution comprising a mixture of a polymer, optionally polyvinyl alcohol (PVA) or polyethylene glycol (PEG), and a metal nitrate, wherein the metal nitrate comprises an ion of an element corresponding to the element of the optical material, and pulverizing the foam to provide the powder; or (ii) co-precipitating a powder by adding an aqueous solution containing a mixture of a metal nitrate containing an element ion corresponding to the element of the optical material and ammonium sulfate to an aqueous solution of ammonium carbonate.

18. A method for preparing an optical material according to any one of claims 1 to 12, wherein the method comprises preparing a ceramic of the optical material by a technique selected from the group consisting of sintering, hot pressing, hot isostatic pressing and spark plasma synthesis, optionally using binary oxides as starting materials.

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