33 results about "Magnesium niobate" patented technology

A method of producing a refractory metal powder that includes providing a metal powder containing magnesium tantalate or magnesium niobate; and heating the powder in an inert atmosphere in the presence of magnesium, calcium and / or aluminum to a temperature sufficient to remove magnesium tantalate or magnesium niobate from the powder and / or heating the powder under vacuum to a temperature sufficient to remove magnesium tantalate or magnesium niobate from the powder, the heating steps being performed in any order. The metal powder can be formed into pellets at an appropriate sintering temperature, which can be formed into electrolytic capacitors.

The invention provides a method for preparing lead-titanate-lead-magnesium niobate films by pulsed laser deposition assisted by oxygen plasmas, which is characterized by introducing high-activity oxygen plasmas to the process of preparing lead titanium-magnesium niobate films by pulsed laser deposition and improving the crystallinity and topography of the oxygen plasmas, thus obtaining the high-quality lead titanium-magnesium niobate films. The specific process is as follows: placing the lead-titanate-lead-magnesium niobate target and the substrate into a vacuum chamber; vacuumizing the vacuum chamber and heating the substrate to certain temperature; then pumping certain amount of high-purity oxygen and ionizing the oxygen by using a gas ionization system to apply high pressure to form the high-activity oxygen plasmas; ensuring the oxygen plasmas between the lead-titanate-lead-magnesium niobate target and the substrate; and using the high energy pulse laser to bombard the lead-titanate-lead-magnesium niobate target to generate the high energy plasmas and depositing the lead-titanate-lead-magnesium niobate films on the substrate. The films prepared by the invention have good crystallization quality, compact structure and excellent dielectric and ferroelectric properties.

The invention discloses a multi-field controllable resistive random access memory with a multi-layer film structure and a preparation method thereof. The resistive random access memory is composed of a piezoelectric substrate, a conductive lower electrode, a ferroelectric thin film layer, an upper electrode thin film layer and a gate electrode, wherein the piezoelectric substrate is made from a PMN-PT (Plumbum Magnesium Niobate ) single crystal material; the conductive lower electrode is a manganite thin film; the ferroelectric thin film layer is a BaTiO3 or BiFeO3 ferroelectric thin film; the upper electrode layer and the gate electrode are Pt, Au or Al conductive thin films. The preparation method of the memory comprises the steps of depositing the conductive lower electrode thin film layer on the piezoelectric substrate, next, depositing the single ferroelectric thin film layer or a heterojunction, and finally, depositing the upper electrode thin film and the gate electrode. The memory of the structure has excellent electro-resistive effect, and the electro-resistance can be regulated dynamically by virtue of a field effect structure established with the piezoelectric substrate, and therefore, multi-field regulation and control of the resistive state of a memory device are realized and the design flexibility of the memory can be improved; the multi-field controllable resistive random access memory with the multi-layer film structure is significant for increasing the manufacturing quantity of data memory devices in China.

The invention belongs to the field of light-emitting materials, and particularly relates to europium-doped barium magnesium niobate (BMN) red phosphor. The expression is Ba(1-x%)Eux%(Mg1 / 3Nb2 / 3)O3, wherein x is larger than or equal to 0.5 and smaller than or equal to 5. A preparation method comprises the steps: a peroxy-Nb-citric acid solution is prepared; a BMN:Eu precursor solution is prepared through an aqueous solution gel method; and after the BMN:Eu precursor solution is dried and calcined, the BMN:Eu phosphor is prepared. The obtained phosphor is even in particle size distribution and good in chemical stability, can emit red light with the high intensity and the good color purity under stimulation of near ultraviolet, and can be used for solving the problems that a WLED lacks in theefficient red phosphor, consequently the color rendering index is low, and the color temperature is high and is bias towards cold white.

The invention discloses a bismuth magnesium niobate modified potassium sodium niobate transparent ferroelectric ceramic material and a preparation method thereof adopting low purity raw materials. The formula of the ceramic material is (1-x)(K<0.5>Na<0.5>)Nb<3-x>Bi(Mg<1 / 3>Nb<2 / 3>)O3, wherein x represents the mole number of Bi(Mg<1 / 3>Nb<2 / 3>)O3 and is in a range of 0.03 to 0.09. Low purity raw materials are used, the preparation method comprises steps of preparing raw materials, pre-burning, ball-milling, granulating, pressing, rubber discharging, pressure-free sealed sintering, polishing, and silver ink firing; the ceramic material has the advantages of high light transmission, optical isotropy, strong practicality, and easy production, moreover, the preparation method is simple, the repeatability is good, and the yield is high. The test results show that when x is equal to 0.07, the optical transmission rate of the ceramic material is 70% or more in the visible light and infrared areas, at the same time, the ceramic material has good electric properties: the maximal dielectric constant is 3337, the dielectric loss is less than 3%, the remnant polarization is 1.5 [mu]C / cm2, and the coercive field is 7.0 kV / cm.

The invention discloses a preparation method of a bismuth-based thin film with a high tuning rate: first, a substrate is cleaned, and then a zinc-bismuth niobate induction layer is prepared on the substrate, and then annealing is performed at 650°C-750°C; Then deposit and prepare the magnesium bismuth niobate thin film layer on the substrate with the zinc bismuth niobate induction layer, and finally anneal at 750° C. to prepare the magnesium bismuth niobate thin film with high tuning rate bismuth base structure. Compared with the prior art, the invention has better crystallinity, significantly improved orientation and tuning performance, and the tuning rate increases from 30% to 35%.

The invention belongs to the field of ferroelectric film materials and relates to a method for preparing a plumbum magnesium niobate-plumbum titanate (PMN-PT) ferroelectric film. The method comprises the following steps of: firstly, preparing a PMN-PT ceramic target; secondly, cleaning a silicon (Si) substrate; thirdly, preparing a LaNiO3 conductive buffer layer; and finally, preparing the PMN-PTferroelectric film. The method for preparing the PMN-PT ferroelectric film has the advantages of simple process, high repeatability, capacity of preparing the large-area PMN-PT film with pure perovskite structure preferred orientation on a cheap silicon substrate with an actual application value, compatibility with a Si integrated process, low preparation cost and contribution to mass production of devices. The prepared film has the advantages of high ferroelectric properties and suitability for ferroelectric-semiconductor integrated devices.

The invention discloses a preparation method of a voltage-controlled varactor made of transparent bismuth magnesium niobate thin films. The preparation method comprises following steps: Bi1.5MgNb1.5 O7 target material is prepared by solid state sintering method, wherein the firing temperature is 1150 to 1180 DEG C; a clean and dry indium tin oxid glass substrate is placed on a magnetron sputtering sample stage, Ar and O2 are used as sputtering gases, the Bi1.5MgNb1.5 O7 thin films are obtained by deposition, and then the Bi1.5MgNb1.5 O7 thin films are added into a furnace in oxygen atmosphere for post-annealing treatment; and metal electrodes are prepared on the Bi1.5MgNb1.5 O7 thin films by using mask version. Transparency of the varactor is high; tunability is moderate, device stability is high, preparation technologies are simple, electrode performances are excellent, no heavy metal poisoning or pollution is caused in preparation processes, and application prospect is promising.