Compound rubidium fluoro boroscillate and rubidium fluoro boroscillate nonlinear optical crystal, preparation method and application

Abstract

The present application relates to a compound rubidium fluoroscanate and a rubidium fluoroscanate nonlinear optical crystal, and a preparation method and application thereof. The compound has a chemical formula of Rb2ScB3O6F2, a molecular weight of 382.33 g / mol, and is prepared by a high-temperature vacuum tube sealing method and a solid phase synthesis method. The crystal has a chemical formula of Rb2ScB3O6F2, a molecular weight of 382.33 g / mol, and is crystallized in a monoclinic system and belongs to a non-centrosymmetric space group: P 21, and a unit cell parameter is: a = 4.0372(10) Å, b = 11.800(3) Å, c = 8.823(2) Å, α = gamma = 90°, β = 98.327(11)°, Z = 2, and is grown by a flux method. The obtained crystal has the advantages of a short absorption cutoff edge, a large nonlinear optical effect, good thermal stability, stable physical and chemical properties and the like. The crystal can be used for preparing a frequency doubling generator, an upper and lower frequency converter, and a nonlinear optical device in an optical parametric oscillator, and has important uses in the fields of optics, military, laser lithography and communication.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of preparation of nonlinear optical crystals, and particularly relates to a compound Rb2ScB3O6F2, a nonlinear optical crystal of Rb2ScB3O6F2, and a preparation method and application thereof. BACKGROUND

[0002] The generation of laser has aroused great interest in the research and application of laser technology. Laser generated by a laser can be frequency converted through a nonlinear optical device to obtain more useful wavelengths of laser, which has important applications in the fields of laser frequency expansion, ultra-short / ultra-strong laser pulse, optical communication, etc. Nonlinear optical crystal material, as an important part of all-solid-state laser, plays an important role in the field of modern laser science. According to the working waveband, nonlinear optical crystals can be divided into four wavebands, namely deep ultraviolet waveband (DUV, <200 nm), ultraviolet waveband (UV, 200-400 nm), visible / near-infrared waveband (Vis-NIR, 0.4-3 μm), and medium / far-infrared waveband (M-FIR, including 3-5 and 8-13 μm atmospheric transparent windows). Among them, deep ultraviolet nonlinear optical (NLO) materials play a crucial role in laser frequency conversion, ultra-high resolution lithography and high-precision microprocessing.

[0003] According to the anion group theory, the properties of a material are determined by anion groups. Groups such as [BO2], [BO3], and [B3O6] with a planar configuration exhibit large polarizability anisotropy and superpolarizability, which is conducive to obtaining large birefringence and frequency doubling effect. Among them, the [B3O6] group is considered as one of the best groups for designing and synthesizing ultraviolet and deep ultraviolet nonlinear optical crystals, as the functional group of the best commercialized crystal β-BaB2O4 (β-BBO). The β-BBO crystal has a frequency doubling effect of 5.6 times that of KDP and a large birefringence of 0.12, but due to the insufficient short cutoff edge and the large dispersion caused by the heavy cation, the β-BBO cannot output deep ultraviolet laser by direct frequency doubling. Therefore, it is urgent to develop nonlinear optical crystal materials that have excellent nonlinear optical properties and can output deep ultraviolet frequency-doubled light. SUMMARY

[0004] The present application aims to provide a compound rubidium fluoroscalite, which has a chemical formula of Rb2ScB3O6F2 and a molecular weight of 382.33 g / mol, and is prepared by a high-temperature vacuum tube sealing method or a solid-phase synthesis method.

[0005] Another object of the present application is to provide a nonlinear optical crystal of rubidium fluoroscalite, which has a chemical formula of Rb2ScB3O6F2 and a molecular weight of 382.33 g / mol, and does not contain a symmetry center, belongs to a monoclinic crystal system P21 space group, and has a unit cell parameter of: Alpha = gamma = 90°, beta = 98.327(11)°, Z = 2.

[0006] Another object of the present application is to provide a preparation method of the Rb2ScB3O6F2 nonlinear optical crystal.

[0007] Still another object of the present application is to provide the use of the Rb2ScB3O6F2 nonlinear optical crystal.

[0008] The compound Rb2ScB3O6F2 according to the present application has a chemical formula of Rb2ScB3O6F2, a molecular weight of 382.33 g / mol, and is crystallized in a monoclinic system and belongs to a non-centrosymmetric space group: P21. Alpha = gamma = 90°, beta = 98.327(11)°, Z = 2, and is prepared by a high-temperature vacuum tube sealing method or a solid phase synthesis method.

[0009] The preparation method of the compound Rb2ScB3O6F2 is prepared by the high-temperature vacuum tube sealing method or the solid phase synthesis method, and the specific operation is performed according to the following steps:

[0010] The high-temperature vacuum tube sealing method for preparing the compound Rb2ScB3O6F2 is as follows:

[0011] The Rb source material is RbF, Rb2CO3, RbNO3 or RbBF4, the Sc source material is Sc2O3, ScF3 or Sc(NO3)3, the B source material is B2O3, and the material A is PbO or LiF, which are mixed according to a molar ratio of Rb:Sc:B:A = 2:1:3-5:0-3, and then are loaded into a clean graphite crucible. -3 Pa, and after being sealed at high temperature, is placed in a muffle furnace, heated to 650-750°C at a speed of 20°C / h, kept at constant temperature for 28-33h, then cooled to 400-520°C at a speed of 1°C / h, and finally quickly cooled to room temperature in 2-3 days, to obtain the compound Rb2ScB3O6F2.

[0012] The solid phase synthesis method for preparing the compound Rb2ScB3O6F2 is as follows:

[0013] The Rb source material is RbF, Rb2CO3, RbNO3 or RbBF4, the Sc source material is Sc2O3, ScF3 or Sc(NO3)3, and the B source material is B2O3 or H3BO3 in a clean corundum mortar in a molar ratio of Rb:Sc:B = 2:1:3, and grinding for 1 h, then the mixed raw materials are pressed into a tablet with a diameter of 2 cm by using a tablet press mold, and placed in a corundum crucible with a diameter of 5-10 cm, and the crucible is placed in a single crystal growth furnace with a programmed temperature, and the temperature is raised to 650-670°C at a rate of 20-28°C / h for solid phase reaction, and the sample is taken out and ground for 3-4 times for 0.5 h each time during the heat preservation, and then powder XRD test is performed, and when the measured powder XRD is consistent with the theoretical value, the sample is placed in the furnace for heat preservation for 4-10 days, and finally cooled to room temperature at a rate of 20°C / day to obtain the Rb2ScB3O6F2 compound.

[0014] A rubidium fluoroboroscandate nonlinear optical crystal, the chemical formula of the crystal is Rb2ScB3O6F2, the molecular weight is 382.33 g / mol, the crystal is crystallized in a monoclinic system, belongs to a non-centrosymmetric space group: P21, and the cell parameters are: α = γ = 90°, β = 98.327(11)°, Z = 2, and the crystal is grown by a flux method.

[0015] The preparation method of the rubidium fluoroboroscandate nonlinear optical crystal, the crystal is grown by a flux method, and the specific operation is performed according to the following steps:

[0016] a. The Rb source material is RbF, Rb2CO3, RbNO3 or RbBF4, the Sc source material is Sc2O3, ScF3 or Sc(NO3)3, and the B source material is B2O3 or H3BO3 in a clean corundum mortar in a molar ratio of Rb:Sc:B = 2:1:3, and grinding for 1 h, then the mixed raw materials are pressed into a tablet with a diameter of 2 cm by using a tablet press mold, and placed in a corundum crucible with a diameter of 5-10 cm, and the crucible is placed in a single crystal growth furnace with a programmed temperature, and the temperature is raised to 650-670°C at a rate of 20-28°C / h for solid phase reaction, and the sample is taken out and ground for 3-4 times for 0.5 h each time during the heat preservation, and then powder XRD test is performed, and when the measured powder XRD is consistent with the theoretical value, the sample is placed in the furnace for heat preservation for 4-10 days, and finally cooled to room temperature at a rate of 20°C / day to obtain the Rb2ScB3O6F2 compound;

[0017] b. The compound obtained in step a is added to a fluxing agent, PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF or MoO3, and placed in a Φ40 mm x 50 mm open ended platinum crucible, which is placed in a single crystal growth furnace with programmed temperature control. The platinum crucible is heated at a rate of 50°C / h to a temperature of 780-850°C, and held at this temperature for 24-42 h. The temperature is then decreased at a rate of 1-2°C / h to 730-780°C to obtain a mixed melt;

[0018] or the Rb source material, RbF, Rb2CO3, RbNO3 or RbBF4, the Sc source material, Sc2O3, ScF3 or Sc(NO3)3, and the B source material, B2O3 or H3BO3, are added to a fluxing agent, PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF or MoO3, in a molar ratio of Rb:Sc:B = 2:1:3, and placed in a Φ40 mm x 50 mm open ended platinum crucible, which is placed in a single crystal growth furnace with programmed temperature control. The platinum crucible is heated at a rate of 50°C / h to a temperature of 780-850°C, and held at this temperature for 24-42 h. The temperature is then decreased at a rate of 1-2°C / h to 730-780°C to obtain a mixed melt;

[0019] c. The mixed melt obtained in step b is slowly cooled at a rate of 0.5-3°C / h to room temperature to crystallize, to obtain a seed crystal;

[0020] d. The seed crystal obtained in step c is fixed on a seed crystal rod, and the seed crystal is lowered from the top of the crystal growth furnace to contact the surface of the mixed melt, and held for 10 min. The temperature is then decreased at a rate of 0.5-1°C / h to 700-710°C, and the seed crystal rod is rotated at a rate of 5-7 rpm. When the crystal has grown to the desired size, the crystal is separated from the melt liquid surface, and the temperature is decreased at a rate of 20°C / h to room temperature. The crystal is then slowly removed from the furnace, to obtain the Rb2ScB3O6F2 nonlinear optical crystal.

[0021] or the compound obtained in step a is added to a fluxing agent, PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF or MoO3, and placed in a Φ20 mm x 50 mm flanged platinum crucible, which is placed in a single crystal growth furnace with programmed temperature control. The platinum crucible is heated at a rate of 5-20°C / h to a temperature of 680-720°C, and held at this temperature for 72 h to obtain a mixed melt. The temperature is then decreased at a rate of 20°C / d to 400-480°C, and then decreased to room temperature over a period of 1-2 days to obtain the Rb2ScB3O6F2 nonlinear optical crystal.

[0022] or directly adding Rb source material RbF, Rb2CO3, RbNO3 or RbBF4, Sc source material Sc2O3, ScF3 or Sc(NO3)3, B source material B2O3 or H3BO3 into fluxing agent PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF or MoO3, and putting into Φ20mm×50mm flange sealing platinum crucible, and putting the platinum crucible into program-controlled temperature single crystal growth furnace, heating to 680-720℃ at a speed of 5-20℃ / h, keeping constant temperature for 72h to obtain mixed melt, then cooling to 400-480℃ at a cooling rate of 20℃ / d, and then cooling to room temperature in 1-2 days to obtain Rb2ScB3O6F2 nonlinear optical crystal.

[0023] The Rb2ScB3O6F2 nonlinear optical crystal is used in the preparation of frequency doubler, upper and lower frequency converter and optical parametric oscillator.

[0024] The compound Rb2ScB3O6F2 and the preparation method and use of the Rb2ScB3O6F2 nonlinear optical crystal must ensure that at least one of the source materials is fluoride when the raw materials are selected and combined.

[0025] The Rb2ScB3O6F2 polycrystalline powder (i.e. compound) prepared by the solid phase synthesis method can be prepared by the following chemical reaction formula:

[0026] (1) 2RbF+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2;

[0027] (2) RbF+RbBF4+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2+BF3↑;

[0028] (3) 2RbF+ScF3+2B2O3=Rb2ScB3O6F2+BF3↑;

[0029] (4) 2RbF+Sc(NO3)3+3H3BO3=Rb2ScB3O6F2+3NO2↑+4.5H2O↑+0.75O2↑;

[0030] (5) 4RbNO3+2ScF3+6H3BO3=2Rb2ScB3O6F2+F2↑+9H2O↑+4NO2↑+0.5O2↑;

[0031] (6) Rb2CO3+ScF3+3H3BO3=Rb2ScB3O6F2+HF↑+4H2O↑+CO2↑。

[0032] The Rb2ScB3O6F2 nonlinear optical crystal obtained by the method has a millimeter level size, and a large size Rb2ScB3O6F2 nonlinear optical crystal can be obtained by using a large size crucible and prolonging the growth period.

[0033] According to the crystallographic data of the crystal, the crystal blank is oriented, the crystal is cut according to a required angle, thickness and cross-sectional size, and the light transmission surface of the crystal is polished, so that the crystal can be used as a nonlinear optical device.

[0034] The working principle of the nonlinear optical device is that at least one piece of Rb2ScB3O6F2 nonlinear optical crystal is used to generate at least one piece of output radiation with a different frequency from the incident electromagnetic radiation.

[0035] Compared with the prior art, the Rb2ScB3O6F2 nonlinear optical crystal has the following beneficial effects:

[0036] (1) The Rb2ScB3O6F2 nonlinear optical crystal has good optical performance, an optical shortest transmission of less than 175 nm, a large nonlinear optical effect of 1.4xKDP, can meet a type of phase matching, a calculated birefringence of 0.088 at 1064 nm, a shortest phase matching wavelength of 182 nm, and is expected to be used in a frequency doubling conversion process in a deep ultraviolet region;

[0037] (2) The Rb2ScB3O6F2 nonlinear optical crystal has no inclusions in the growth process and a relatively fast growth speed;

[0038] (3) The Rb2ScB3O6F2 nonlinear optical crystal can be used to manufacture a nonlinear optical device;

[0039] (4) The Rb2ScB3O6F2 nonlinear optical crystal obtained by the method can be used to manufacture a nonlinear optical device, which has important uses in the fields of optics, military, laser lithography and communication. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The Rb2ScB3O6F2 nonlinear optical crystal obtained by the method has a millimeter level size, and a large size Rb2ScB3O6F2 nonlinear optical crystal can be obtained by using a large size crucible and prolonging the growth period.

[0041] Figure 2Figure 1 is a structural schematic diagram of the Rb2ScB3O6F2 nonlinear optical crystal of the present application, wherein (a) is a basic building block, (b) is a connection mode of [ScO3F3] and [B3O6] groups, (c) is an arrangement mode of the [B3O6] group observed from the c-axis, and (d) is an overall structure of Rb2ScB3O6F2 observed from the c-axis, isolated [B3O6] groups are connected by [ScO3F3] polyhedrons, Rb atoms fill the pores to balance the charge and support the structure.

[0042] Figure 3 Figure 2 is a schematic diagram of the SHG effect of the Rb2ScB3O6F2 nonlinear optical crystal of the present application in different particle size ranges, in the particle size range of 150-212 nm, the Rb2ScB3O6F2 exhibits a larger NLO response, about 1.4 times that of KDP.

[0043] Figure 4 Figure 3 is a working principle diagram of a nonlinear optical device made of the Rb2ScB3O6F2 crystal of the present application, wherein 1 is a laser, 2 is an emitted light beam, 3 is the Rb2ScB3O6F2 nonlinear optical crystal after treatment and optical processing, 4 is a light beam, and 5 is a filter. DETAILED DESCRIPTION

[0044] In order to make the innovative content of the present application more convenient to understand, the present application is described in detail in combination with the drawings and examples of the present application, but is not limited to the present application. The raw materials or equipment used in the present application, if not specifically stated, are commercially available.

[0045] Example 1

[0046] According to the chemical reaction formula 2RbF+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2, the compound Rb2ScB3O6F2 is prepared by a high-temperature vacuum sealing tube method, and the specific operation is performed according to the following steps:

[0047] RbF, Sc2O3, B2O3 and A are PbO, respectively, in a molar ratio of 2:0.5:1.5:1, and the total amount of 0.5 g is weighed, mixed uniformly, and then loaded into a clean graphite crucible. Then the graphite crucible is placed in a quartz tube with a length of 24 cm and a diameter of 12 mm, and the quartz tube is pumped to 10 -3 Pa vacuum degree, and then the sealed quartz tube is placed in a program-controlled muffle furnace, and the temperature is raised to 720℃ at a rate of 20℃ / h, and then the temperature is kept for 33h, and then the temperature is lowered to 520℃ at a rate of 1℃ / h, and then the temperature is lowered to room temperature in 3 days, to obtain the compound Rb2ScB3O6F2.

[0048] Example 2

[0049] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2RbF+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2, and the specific operation is performed according to the following steps:

[0050] RbF, RbBF4, Sc2O3, B2O3 and A are PbO respectively according to the molar ratio of 1:1:0.5:1.5:1, and then the mixture is loaded into a clean graphite crucible, and then the graphite crucible is placed into a quartz tube with a length of 24 cm and a diameter of 12 mm, and the quartz tube is pumped to 10 -3 Pa vacuum degree, and then the sealed quartz tube is placed into a program-controlled muffle furnace, and the temperature is increased to 710 ℃ at a rate of 20 ℃ / h, and then the temperature is kept for 32 h, and then the temperature is decreased to 510 ℃ at a rate of 1 ℃ / h, and then the temperature is decreased to room temperature in 3 days, and the compound Rb2ScB3O6F2 is obtained.

[0051] Example 3

[0052] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2RbF+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2, and the specific operation is performed according to the following steps:

[0053] RbF, Sc(NO3)3, B2O3 and A are LiF respectively according to the molar ratio of 2:1:1.5:3, and then the mixture is loaded into a clean graphite crucible, and then the graphite crucible is placed into a quartz tube with a length of 24 cm and a diameter of 12 mm, and the quartz tube is pumped to 10 -3 Pa vacuum degree, and then the sealed quartz tube is placed into a program-controlled muffle furnace, and the temperature is increased to 710 ℃ at a rate of 20 ℃ / h, and then the temperature is kept for 32 h, and then the temperature is decreased to 510 ℃ at a rate of 1 ℃ / h, and then the temperature is decreased to room temperature in 3 days, and the compound Rb2ScB3O6F2 is obtained.

[0054] Example 4

[0055] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2RbF+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2, and the specific operation is performed according to the following steps:

[0056] RbF, Sc2O3 and B2O3 are weighed according to the molar ratio of 2:0.5:2.5, and then the mixture is loaded into a clean graphite crucible, and then the graphite crucible is placed into a quartz tube with a length of 24 cm and a diameter of 12 mm, and the quartz tube is pumped to 10-3 After the vacuum degree Pa, melt sealing is carried out. The sealed quartz tube is placed into a program-controlled muffle furnace, and the temperature is raised to 750°C at a rate of 20°C / h, and then the temperature is kept for 33 h. Then the temperature is lowered to 450°C at a rate of 1°C / h, and then the temperature is lowered to room temperature in 2 days, so that the compound Rb2ScB3O6F2 is obtained.

[0057] Example 5

[0058] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2Rb2CO3+2ScF3+3B2O3=2Rb2ScB3O6F2+3F2↑+CO↑+CO2↑, and the specific operation is carried out according to the following steps:

[0059] Rb2CO3, ScF3 and B2O3 are weighed according to a molar ratio of 1:1:2, and the total amount is 0.5 g. After being mixed uniformly, they are loaded into a clean graphite crucible, and then the graphite crucible is placed into a quartz tube with a length of 24 cm and a diameter of 12 mm. The quartz tube is pumped to a vacuum degree of 10 -3 After the vacuum degree Pa, melt sealing is carried out. The sealed quartz tube is placed into a program-controlled muffle furnace, and the temperature is raised to 680°C at a rate of 20°C / h, and then the temperature is kept for 30 h. Then the temperature is lowered to 480°C at a rate of 1°C / h, and then the temperature is lowered to room temperature in 2 days, so that the compound Rb2ScB3O6F2 is obtained.

[0060] Example 6

[0061] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 4RbNO3+2ScF3+3B2O3=2Rb2ScB3O6F2+F2↑+4NO2↑+0.5O2↑, and the specific operation is carried out according to the following steps:

[0062] RbNO3, ScF3 and B2O3 are weighed according to a molar ratio of 2:1:2, and the total amount is 0.5 g. After being mixed uniformly, they are loaded into a clean graphite crucible, and then the graphite crucible is placed into a quartz tube with a length of 24 cm and a diameter of 12 mm. The quartz tube is pumped to a vacuum degree of 10 -3 After the vacuum degree Pa, melt sealing is carried out. The sealed quartz tube is placed into a program-controlled muffle furnace, and the temperature is raised to 680°C at a rate of 20°C / h, and then the temperature is kept for 30 h. Then the temperature is lowered to 480°C at a rate of 1°C / h, and then the temperature is lowered to room temperature in 2 days, so that the compound Rb2ScB3O6F2 is obtained.

[0063] Example 7

[0064] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2RbF+ScF3+2B2O3=Rb2ScB3O6F2+BF3↑, and the specific operation is performed according to the following steps:

[0065] RbF, ScF3 and B2O3 are weighed according to a molar ratio of 2:1:2.5, and a total amount of 0.5 g, mixed uniformly, and then loaded into a clean graphite crucible. Then the graphite crucible is placed in a quartz tube with a length of 24 cm and a diameter of 12 mm. The quartz tube is pumped to 10 -3 Pa vacuum degree, and then the sealed quartz tube is placed in a program-controlled muffle furnace, and the temperature is raised to 670 ℃ at a rate of 20 ℃ / h, and then the temperature is kept for 28 h. Then the temperature is lowered to 470 ℃ at a rate of 1 ℃ / h, and then the temperature is lowered to room temperature in 2 days. Thus the compound Rb2ScB3O6F2 is obtained.

[0066] Example 8

[0067] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2RbF+ScF3+2B2O3=Rb2ScB3O6F2+BF3↑, and the specific operation is performed according to the following steps:

[0068] RbF, ScF3 and B2O3 are weighed according to a molar ratio of 2:1:2, and a total amount of 0.5 g, mixed uniformly, and then loaded into a clean graphite crucible. Then the graphite crucible is placed in a quartz tube with a length of 24 cm and a diameter of 12 mm. The quartz tube is pumped to 10 - 3 Pa vacuum degree, and then the sealed quartz tube is placed in a program-controlled muffle furnace, and the temperature is raised to 680 ℃ at a rate of 20 ℃ / h, and then the temperature is kept for 32 h. Then the temperature is lowered to 480 ℃ at a rate of 1 ℃ / h, and then the temperature is lowered to room temperature in 2 days. Thus the compound Rb2ScB3O6F2 is obtained.

[0069] Example 9

[0070] The compound Rb2ScB3O6F2 is prepared by high-temperature vacuum tube sealing method according to the chemical reaction formula 2RbF+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2, and the specific operation is performed according to the following steps:

[0071] RbF, Sc2O3 and B2O3 were weighed according to the molar ratio of 2:0.5:1.5, and the total amount was 5 g, and then mixed uniformly, and then put into a clean corundum mortar, and then grinded for 1 h, and then the uniformly mixed raw materials were pressed into a tablet with a diameter of 2 cm by using a tablet press mold, and then the tablet was placed in a corundum crucible with a diameter of 5 cm, and then the crucible was placed in a single crystal growth furnace with a program-controlled temperature, and then the temperature was increased to 660 DEG C at a rate of 25 DEG C / h for solid-phase reaction, and then the sample was taken out and grinded for 3 times during the heat preservation, and then the sample was put into the furnace for heat preservation for 5 days, and then the sample was cooled to room temperature at a rate of 20 DEG C / day, and then the compound Rb2ScB3O6F2 was obtained.

[0072] Example 10

[0073] The compound Rb2ScB3O6F2 was prepared by using a solid-phase synthesis method according to the chemical reaction formula RbF+RbBF4+0.5Sc2O3+1.5B2O3=Rb2ScB3O6F2+BF3↑, and the specific operation was carried out according to the following steps:

[0074] RbF, RbBF4, Sc2O3 and B2O3 were weighed according to the molar ratio of 1:1:0.5:1.5, and the total amount was 5 g, and then mixed uniformly, and then put into a clean corundum mortar, and then grinded for 1 h, and then the uniformly mixed raw materials were pressed into a tablet with a diameter of 2 cm by using a tablet press mold, and then the tablet was placed in a corundum crucible with a diameter of 5 cm, and then the crucible was placed in a single crystal growth furnace with a program-controlled temperature, and then the temperature was increased to 650 DEG C at a rate of 25 DEG C / h for solid-phase reaction, and then the sample was taken out and grinded for 3 times during the heat preservation, and then the sample was put into the furnace for heat preservation for 4 days, and then the sample was cooled to room temperature at a rate of 20 DEG C / day, and then the compound Rb2ScB3O6F2 was obtained.

[0075] Example 11

[0076] The compound Rb2ScB3O6F2 was prepared by using a solid-phase synthesis method according to the chemical reaction formula 2RbF+ScF3+2B2O3=Rb2ScB3O6F2+BF3↑, and the specific operation was carried out according to the following steps:

[0077] RbF, ScF3 and B2O3 were weighed according to the molar ratio of 2:1:2, and the total amount was 10 g, and then mixed uniformly, and then put into a clean corundum mortar, and then grinded for 1 h, and then the uniformly mixed raw materials were pressed into a tablet with a diameter of 2 cm by using a tablet press mold, and then the tablet was placed in a corundum crucible with a diameter of 10 cm, and then the crucible was placed in a single crystal growth furnace with a program-controlled temperature, and then the temperature was increased to 670 DEG C at a rate of 28 DEG C / h for solid-phase reaction, and then the sample was taken out and grinded for 3 times during the heat preservation, and then the sample was put into the furnace for heat preservation for 10 days, and then the sample was cooled to room temperature at a rate of 20 DEG C / day, and then the compound Rb2ScB3O6F2 was obtained.

[0078] Example 12

[0079] The compound Rb2ScB3O6F2 is prepared by solid phase synthesis according to the chemical reaction formula 2RbF + Sc(N03)3 + 3H3B03= Rb2ScB3O6F2 + 3N02↑ + 4.5H20↑ + 0.75O2↑, and the specific operation is performed according to the following steps:

[0080] RbF, Sc(N03)3 and H3B03 are weighed according to the molar ratio of 2:1:3, and the total amount is 3g, which are mixed uniformly and put into a clean corundum mortar, and grinded for 1h. Then the uniformly mixed raw materials are pressed into a tablet with a diameter of 2cm by using a tablet press mold, and placed in a corundum crucible with a diameter of 5cm. The crucible is placed in a single crystal growth furnace with programmed temperature, and the temperature is raised to 650℃ at a rate of 20℃ / h, and kept for 5 days. During the heat preservation period, the sample is taken out and grinded for 4 times, each time for half an hour. Then the sample is put into the furnace and kept for 5 days, and then cooled to room temperature at a rate of 20℃ / day. The compound Rb2ScB3O6F2 is obtained.

[0081] Example 13

[0082] The compound Rb2ScB3O6F2 is prepared by solid phase synthesis according to the chemical reaction formula 4RbN03 + 2ScF3 + 6H3B03 = 2Rb2ScB3O6F2 + F2↑ + 9H20↑ + 4N02↑ + 0.5O2↑, and the specific operation is performed according to the following steps:

[0083] RbN03, ScF3 and H3B03 are weighed according to the molar ratio of 4:2:6, and the total amount is 7g, which are mixed uniformly and put into a clean corundum mortar, and grinded for 1h. Then the uniformly mixed raw materials are pressed into a tablet with a diameter of 2cm by using a tablet press mold, and placed in a corundum crucible with a diameter of 10cm. The crucible is placed in a single crystal growth furnace with programmed temperature, and the temperature is raised to 670℃ at a rate of 24℃ / h, and kept for 5 days. During the heat preservation period, the sample is taken out and grinded for 4 times, each time for half an hour. Then the sample is put into the furnace and kept for 6 days, and then cooled to room temperature at a rate of 20℃ / day. The compound Rb2ScB3O6F2 is obtained.

[0084] Example 14

[0085] The compound Rb2ScB3O6F2 is prepared by solid phase synthesis according to the chemical reaction formula Rb2C03 + ScF3 + 3H3B03 = Rb2ScB3O6F2 + HF↑ + 4H20↑ + C02↑, and the specific operation is performed according to the following steps:

[0086] Rb2CO3, ScF3 and H3BO3 were weighed according to a molar ratio of 1:1:3, with a total amount of 10 g, mixed uniformly, put into a clean corundum mortar, and ground for 1 h. Then the uniformly mixed raw materials were pressed into a tablet with a diameter of 2 cm by using a tablet press mold. The tablet was put into a corundum crucible with a diameter of 10 cm. The crucible was put into a single crystal growth furnace with a programmed temperature. The temperature was increased to 660 ℃ at a rate of 20 ℃ / h, and then kept for 4 days. During the keeping, the sample was taken out and ground for 4 times, with each time of 0.5 h. Then the sample was put into the furnace and kept for 10 days. The sample was cooled to room temperature at a rate of 20 ℃ / day. Thus, the Rb2ScB3O6F2 compound was obtained.

[0087] Example 15

[0088] The Rb2ScB3O6F2 nonlinear optical crystal was grown by using a flux method. The specific operation was performed according to the following steps:

[0089] The polycrystalline powder Rb2ScB3O6F2 compound obtained in Example 9 and a flux PbO were mixed according to a molar ratio of 1:2, with a total amount of 10 g. The mixture was put into a Φ40 mm×50 mm open platinum crucible. The crucible was put into a single crystal growth furnace. The temperature was increased to 850 ℃ at a rate of 50 ℃ / h, kept for 24 h, and then decreased to 780 ℃ at a rate of 1 ℃ / h. Thus, a mixed melt was obtained.

[0090] The temperature was slowly decreased to room temperature at a rate of 0.5 ℃ / h to crystallize the seed crystal.

[0091] The seed crystal fixed on the seed crystal rod was seeded from the top of the crystal growth furnace, so that the seed crystal contacted with the surface of the mixed melt and stayed for 10 min. Then the temperature was decreased to 710 ℃ at a rate of 0.5 ℃ / h. The seed crystal rod was rotated at a speed of 7 rpm. After the crystal grew to a desired size, the crystal was separated from the melt liquid surface. The temperature was decreased to room temperature at a rate of 20 ℃ / h. Then the crystal was slowly taken out from the furnace. Thus, the Rb2ScB3O6F2 nonlinear optical crystal with a size of 5 mm×3 mm×4 mm was obtained.

[0092] Example 16

[0093] The Rb2ScB3O6F2 nonlinear optical crystal was grown by using a flux method. The specific operation was performed according to the following steps:

[0094] The polycrystalline powder Rb2ScB3O6F2 compound obtained in Example 10 and a flux LiF were mixed according to a molar ratio of 1:10, with a total amount of 10 g. The mixture was put into a Φ40 mm×50 mm open platinum crucible. The crucible was put into a single crystal growth furnace. The temperature was increased to 830 ℃ at a rate of 50 ℃ / h, kept for 30 h, and then decreased to 750 ℃ at a rate of 1.5 ℃ / h. Thus, a mixed melt was obtained.

[0095] Slowly decrease to room temperature at a rate of 1 ℃ / h to crystallize, obtain the seed crystal;

[0096] The seed crystal fixed on the seed crystal rod is seeded from the top of the crystal growth furnace to contact the mixed melt surface, stays for 10 minutes, then decreases to 700 ℃ at a rate of 0.8 ℃ / h, rotates the seed crystal rod at a speed of 6.5 rpm, and after the crystal grows to the required size, separates the crystal from the melt liquid surface, decreases to room temperature at a rate of 20 ℃ / h, and then slowly takes out the crystal from the furnace, to obtain the Rb2ScB3O6F2 nonlinear optical crystal with a size of 4 mm x 3 mm x 2 mm.

[0097] Example 17

[0098] The flux method is used to grow the Rb2ScB3O6F2 nonlinear optical crystal, and the specific operation is performed according to the following steps:

[0099] The polycrystalline powder Rb2ScB3O6F2 compound obtained in Example 11 and the flux 0.5PbF2+0.5PbO are weighed according to a molar ratio of 1:4, with a total amount of 12 g, mixed, and loaded into a Φ40 mm x 50 mm open platinum crucible, the crucible is placed in a single crystal growth furnace, heated to a temperature of 780 ℃ at a rate of 50 ℃ / h, kept at a constant temperature for 42 hours, then decreased to 730 ℃ at a rate of 1.8 ℃ / h, to obtain a mixed melt;

[0100] Slowly decrease to room temperature at a rate of 3 ℃ / h to crystallize, obtain the seed crystal;

[0101] The seed crystal fixed on the seed crystal rod is seeded from the top of the crystal growth furnace to contact the mixed melt surface, stays for 10 minutes, then decreases to 710 ℃ at a rate of 1 ℃ / h, rotates the seed crystal rod at a speed of 7 rpm, and after the crystal grows to the required size, separates the crystal from the melt liquid surface, decreases to room temperature at a rate of 20 ℃ / h, and then slowly takes out the crystal from the furnace, to obtain the Rb2ScB3O6F2 nonlinear optical crystal with a size of 5 mm x 4 mm x 2 mm.

[0102] Example 18

[0103] The flux method is used to grow the Rb2ScB3O6F2 nonlinear optical crystal, and the specific operation is performed according to the following steps:

[0104] Rb2CO3, ScF3, B2O3 and flux PbO are weighed according to a molar ratio of 1:1:1.5:2, respectively, with a total amount of 8 g, mixed, and loaded into a Φ40 mm x 50 mm open platinum crucible, the crucible is placed in a single crystal growth furnace, heated to a temperature of 850 ℃ at a rate of 50 ℃ / h, kept at a constant temperature for 38 hours, then decreased to 760 ℃ at a rate of 1.5 ℃ / h, to obtain a mixed melt;

[0105] Slowly decrease to room temperature crystallization at the rate of 0.5 ℃ / h, obtain the seed crystal;

[0106] The seed crystal fixed on the seed crystal rod is seeded from the top of the crystal growth furnace to contact the mixed melt surface, and stays for 10 minutes, then decreases to 710 ℃ at the rate of 0.8 ℃ / h, rotates the seed crystal rod at the speed of 5 rpm, and after the crystal grows to the required size, the crystal is separated from the melt liquid surface, decreases to room temperature at the rate of 20 ℃ / h, and then slowly takes out the crystal from the furnace, to obtain the Rb2ScB3O6F2 nonlinear optical crystal with the size of 2 mm x 3 mm x 3.5 mm.

[0107] Example 19

[0108] The flux method is used to grow the Rb2ScB3O6F2 nonlinear optical crystal, and the specific operation is carried out according to the following steps:

[0109] RbF, RbBF4, Sc2O3, H3BO3 and flux 0.5PbF2+0.5PbO are weighed according to the molar ratio of 1:1:0.5:3:4, and the total amount is 10 g, mixed and loaded into a Φ40 mm x 50 mm open platinum crucible, the crucible is put into a single crystal growth furnace, heated to a temperature of 780 ℃ at a rate of 50 ℃ / h, kept for 40 hours, and then decreased to 730 ℃ at a rate of 2 ℃ / h, to obtain a mixed melt;

[0110] Slowly decrease to room temperature crystallization at the rate of 3 ℃ / h, obtain the seed crystal;

[0111] The seed crystal fixed on the seed crystal rod is seeded from the top of the crystal growth furnace to contact the mixed melt surface, and stays for 10 minutes, then decreases to 710 ℃ at the rate of 0.5 ℃ / h, rotates the seed crystal rod at the speed of 5.5 rpm, and after the crystal grows to the required size, the crystal is separated from the melt liquid surface, decreases to room temperature at the rate of 20 ℃ / h, and then slowly takes out the crystal from the furnace, to obtain the Rb2ScB3O6F2 nonlinear optical crystal with the size of 3 mm x 3.5 mm x 2 mm.

[0112] Example 20

[0113] The flux method is used to grow the Rb2ScB3O6F2 nonlinear optical crystal, and the specific operation is carried out according to the following steps:

[0114] The polycrystalline powder Rb2ScB3O6F2 compound obtained in Example 12 and fluxing agent 0.5RbCl+0.5CsF are weighed according to a molar ratio of 1:6 with a total amount of 5 g, and are loaded into a Φ20 mm x 50 mm flange-sealed platinum-gold crucible. The crucible is placed in a program-controlled single crystal growth furnace, heated to a temperature of 680℃ at a rate of 20℃ / h, kept at the temperature for 72 hours, then reduced to 480℃ at a rate of 20℃ / d, and finally reduced to room temperature in two days. The flange-sealed crucible is opened to obtain a Rb2ScB3O6F2 nonlinear optical crystal with a size of 5 mm x 6 mm x 3 mm.

[0115] Example 21

[0116] The Rb2ScB3O6F2 nonlinear optical crystal is grown by a flux method, and the specific operation is performed according to the following steps:

[0117] The polycrystalline powder Rb2ScB3O6F2 compound obtained in Example 13 and fluxing agent RbF+RbCl are weighed according to a molar ratio of 1:3 with a total amount of 5 g, and are loaded into a Φ20 mm x 50 mm flange-sealed platinum-gold crucible. The crucible is placed in a program-controlled single crystal growth furnace, heated to a temperature of 720℃ at a rate of 20℃ / h, kept at the temperature for 72 hours, then reduced to 420℃ at a rate of 20℃ / d, and finally reduced to room temperature in one day. The flange-sealed crucible is opened to obtain a Rb2ScB3O6F2 nonlinear optical crystal with a size of 3 mm x 3 mm x 4 mm.

[0118] Example 22

[0119] The Rb2ScB3O6F2 nonlinear optical crystal is grown by a flux method, and the specific operation is performed according to the following steps:

[0120] The polycrystalline powder Rb2ScB3O6F2 compound obtained in Example 14 and fluxing agent 0.5RbCl+0.5CsF are weighed according to a molar ratio of 1:1 with a total amount of 4 g, and are loaded into a Φ20 mm x 50 mm flange-sealed platinum-gold crucible. The crucible is placed in a program-controlled single crystal growth furnace, heated to a temperature of 680℃ at a rate of 5℃ / h, kept at the temperature for 72 hours, then reduced to 480℃ at a rate of 20℃ / d, and finally reduced to room temperature in two days. The flange-sealed crucible is opened to obtain a Rb2ScB3O6F2 nonlinear optical crystal with a size of 3 mm x 3.5 mm x 3 mm.

[0121] Example 23

[0122] The Rb2ScB3O6F2 nonlinear optical crystal is grown by a flux method, and the specific operation is performed according to the following steps:

[0123] RbF, Sc(NO3)3, B2O3 and fluxing agent MoO3 were weighed according to a molar ratio of 2:1:3:3, with a total amount of 3 g, mixed, and put into a Φ20 mm x 50 mm flange-sealed platinum-gold crucible. The crucible was put into a single crystal growth furnace with a program-controlled temperature, heated to a temperature of 700 ℃ at a speed of 15 ℃ / h, kept at the temperature for 72 hours, then reduced to 400 ℃ at a cooling rate of 20 ℃ / d, and finally reduced to room temperature in one day. The flange-sealed crucible was opened, and a Rb2ScB3O6F2 nonlinear optical crystal with a size of 2.5 mm x 3 mm x 2 mm was obtained.

[0124] Example 24

[0125] A Rb2ScB3O6F2 nonlinear optical crystal was grown by a flux method, and the specific operation was performed according to the following steps:

[0126] RbNO3, ScF3, B2O3 and fluxing agent 3RbF+PbO were weighed according to a molar ratio of 4:2:6:1, with a total amount of 3 g, mixed, and put into a Φ20 mm x 50 mm flange-sealed platinum-gold crucible. The crucible was put into a single crystal growth furnace with a program-controlled temperature, heated to a temperature of 690 ℃ at a speed of 10 ℃ / h, kept at the temperature for 72 hours, then reduced to 450 ℃ at a cooling rate of 20 ℃ / d, and finally reduced to room temperature in two days. The flange-sealed crucible was opened, and a Rb2ScB3O6F2 nonlinear optical crystal with a size of 4 mm x 3 mm x 3 mm was obtained.

[0127] Example 25

[0128] A Rb2ScB3O6F2 nonlinear optical crystal was grown by a flux method, and the specific operation was performed according to the following steps:

[0129] RbF, Sc2O3, B2O3 and fluxing agent 3RbF+PbO were weighed according to a molar ratio of 2:0.5:1.5:1, with a total amount of 4 g, mixed, and put into a Φ20 mm x 50 mm flange-sealed platinum-gold crucible. The crucible was put into a single crystal growth furnace with a program-controlled temperature, heated to a temperature of 700 ℃ at a speed of 5 ℃ / h, kept at the temperature for 72 hours, then reduced to 450 ℃ at a cooling rate of 20 ℃ / d, and finally reduced to room temperature in two days. The flange-sealed crucible was opened, and a Rb2ScB3O6F2 nonlinear optical crystal with a size of 2 mm x 3.5 mm x 2.5 mm was obtained.

[0130] Example 26

[0131] It was tested that the Rb2ScB3O6F2 nonlinear optical crystal prepared in Examples 15-25 belonged to a monoclinic system, a space group was P21, the nonlinear optical crystal did not have a center of symmetry, and the unit cell parameters were as follows: α = γ = 90°, β = 98.327(11)°, Z = 2; Figure 1 is a Rb2ScB3O6F2 polycrystalline powder XRD pattern and a simulated diffraction pattern, Figure 2 is a structural schematic diagram of the Rb2ScB3O6F2 nonlinear optical crystal.

[0132] Example 27

[0133] The Rb2ScB3O6F2 crystal obtained in Examples 15-25 is not easy to break, not easy to deliquesce, easy to cut, polish, process and store; a frequency doubler device with a size of 2mm x 3mm x 2mm is processed from the Rb2ScB3O6F2 crystal obtained in Examples 15-25 according to the phase matching direction, and placed at the position of the device marked as 3 in the figure, Figure 4 The Rb2ScB3O6F2 crystal obtained in Examples 15-25 is not easy to break, not easy to deliquesce, easy to cut, polish, process and store; a frequency doubler device with a size of 2mm x 3mm x 2mm is processed from the Rb2ScB3O6F2 crystal obtained in Examples 15-25 according to the phase matching direction, and placed at the position of the device marked as 3 in the figure,

[0134] The use of the Rb2ScB3O6F2 nonlinear optical crystal in the preparation of a frequency doubler, an up-converter, a down-converter and an optical parametric oscillator.

[0135] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that modifications or equivalent replacements to the technical solutions of the present application do not deviate from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A rubidium nonlinear optical crystal of fluoroborate scandium, characterized in that... The crystal has the chemical formula Rb₂ScB₃O₆F₂, a molecular weight of 382.33 g / mol, and crystallizes in the monoclinic system, belonging to the non-central space group. P 21, the unit cell parameters are: a = 4.0372(10)Å, b = 11.800(3) Å, c = 8.823(2) Å, α = γ = 90°, β = 98.327(11) °, Z = 2, crystals are grown using the flux method.

2. The method for preparing a rubidium scandium fluoride nonlinear optical crystal according to claim 1, characterized in that... The crystal growth method using fluxing is performed according to the following steps: a. Using a molar ratio of Rb:Sc:B = 2:1:3, place the Rb source material (RbF, Rb2CO3, RbNO3, or RbBF4), the Sc source material (Sc2O3, ScF3, or Sc(NO3)3), and the B source material (B2O3 or H3BO3) into a clean corundum mortar and grind for 1 hour. Then, press the uniformly mixed raw material into a sheet with a diameter of 2 cm using a pressing mold and place it in a corundum crucible with a diameter of 5-10 cm. Place the crucible in a single crystal growth furnace with a programmable temperature control and raise the temperature to 650-670℃ at a heating rate of 20-28℃ / h for solid-phase reaction. Hold the temperature for 3-5 days. During the holding period, take it out and grind it 3-4 times, each time for half an hour. Then, perform powder XRD test. When the measured powder XRD is consistent with the theoretical value, put the sample back into the furnace and hold it for 4-10 days. Finally, cool it to room temperature at a rate of 20℃ / day to obtain the Rb2ScB3O6F2 compound. b. Add the compound obtained in step a to a flux of PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF, or MoO3, and place it in... Φ In a 40 mm × 50 mm open platinum crucible, the platinum crucible is placed in a temperature-controlled single crystal growth furnace and heated to 780-850℃ at a heating rate of 50℃ / h, held at the temperature for 24-42h, and then cooled to 730-780℃ at a cooling rate of 1-2℃ / h to obtain a mixed melt. Alternatively, directly add RbF, Rb2CO3, RbNO3, or RbBF4 as the Rb source material, Sc2O3, ScF3, or Sc(NO3)3 as the Sc source material, and B2O3 or H3BO3 as the B source material, along with fluxes such as PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF, or MoO3, in a molar ratio of Rb:Sc:B = 2:1:

3. Φ The platinum crucible is placed in a 40 mm × 50 mm open platinum crucible and then placed in a temperature-controlled single crystal growth furnace. The crucible is heated to 780-850°C at a heating rate of 50°C / h and held at that temperature for 24-42 h. The temperature is then reduced to 730-780°C at a cooling rate of 1-2°C / h to obtain a mixed melt. c. The mixed melt obtained in step b is slowly cooled to room temperature at a rate of 0.5-3℃ / h to crystallize and obtain seed crystals; d. Fix the seed crystal obtained in step c onto the seed crystal rod, lower the seed crystal from the top of the crystal growth furnace, so that the seed crystal contacts the surface of the mixed melt, hold for 10 minutes, then cool down to 700-710℃ at a rate of 0.5-1℃ / h, rotate the seed crystal rod at a speed of 5-7 rpm, and after the crystal grows to the required size, remove the crystal from the melt surface, cool it down to room temperature at a rate of 20℃ / h, and then slowly take the crystal out of the furnace to obtain the Rb2ScB3O6F2 nonlinear optical crystal. Alternatively, the compound obtained in step a can be added to a flux such as PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF, or MoO3, and then placed in... Φ The platinum crucible, with its flanged and sealed edges, was placed in a temperature-controlled single crystal growth furnace and heated to 680-720 ℃ at a rate of 5-20 ℃ / h. The mixture was held at this temperature for 72 h to obtain a mixed melt. Then, the temperature was lowered to 400-480 ℃ at a rate of 20 ℃ / d. After cooling to room temperature for 1-2 days, Rb2ScB3O6F2 nonlinear optical crystal was obtained. Alternatively, the Rb source material can be RbF, Rb2CO3, RbNO3, or RbBF4; the Sc source material can be Sc2O3, ScF3, or Sc(NO3)3; and the B source material can be B2O3 or H3BO3. Add fluxes such as PbO, LiF, PbF2+PbO, RbCl+CsF, RbF+RbCl, RbCl+CsF, or MoO3, and place the mixture into the solution. Φ The platinum crucible, with its flanged and sealed edge, is placed in a temperature-controlled single crystal growth furnace and heated to 680-720℃ at a rate of 5-20℃ / h. The mixture is held at this temperature for 72 h to obtain a mixed melt. Then, the temperature is lowered to 400-480℃ at a rate of 20℃ / d, and then cooled to room temperature for 1-2 days to obtain a Rb2ScB3O6F2 nonlinear optical crystal.

3. The use of the Rb2ScB3O6F2 nonlinear optical crystal according to claim 1 in the preparation of frequency doubling generators, up and down frequency converters, and optical parametric oscillators.

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