127 results about "Bridgman method" patented technology

The invention discloses a ternary system relaxation ferroelectric single crystal material. The material comprises the following chemical components: xPb(In1/2Nb1/2)O3-yPb(Mg1/3Nb2/3)O3-(1-x-y)PbTiO3, wherein the x is equal to 0.1-0.45, and the y is equal to 0.1-0.5. A preparation method of the single crystal material PIMNT is an improved Bridgman method and comprises the following steps of: processing raw materials, melting by raising the temperature, and performing crucible degrowth and crystal cooling growth. The prepared single crystal material overcomes the defects of over low Curie point of PMNT single crystals, difficult crystallization and difficult batch growth of the PINT single crystals in the prior art, has high piezoelectric performance and pyroelectric performance, higher temperature stability and wide application prospect and adds a new product in the field.

The invention relates to a FeGa-RE magnetostrictive material and manufacturing technique. The characteristics of magnetostrictive material are that: the ingredient of material consists of Fe, Ga and RE, the content of Ga is 10-40at%, the content of RE is 0.01-20at%, the content of additional intermingle is: C=200-600ppm,N=200-600ppm,O=200-700ppm,other is Fe, the optimal value of Ga is 12-28at%, FeGa-RE magnetostrictive material, the ingredient of material adds one or more kinds of La, Ce, Pr, Nd, Tb, Dy whose content is 0.01-20at%. The manufacturing technique includes the alloy with purified material is cast as the needed round bar, and the alloy bar is crystallized by high temperature gradient flash freezing method and Bridgman method.

The invention provides a method for preparing an IV-VI semiconductor single crystal thin film on a CdZnTe substrate, wherein, in a molecular beam epitaxy(MBE) device, by adopting an MBE growth method and utilizing molecular beam sources of different IV-VI compounds and under different growth temperatures(200 to 425DEG C), the single crystal thin film is epitaxially grown on the CdZnTe single crystal substrate materials; the CdZnTe substrate has a general formula of Cd1-xZnxTe, wherein X is equal to 0 to 0.3; the single crystal thin film grows by the vertical Bridgman method or vapor transport method, is cut along the (111) crystal orientation or (100) crystal orientation, is mechanically polished by Al2O3 powder and then is chemically polished by the bromine-methanol, the concentration of which is 1 percent. The method for preparing an IV-VI semiconductor single crystal thin film on a CdZnTe substrate has the advantages of being capable of realizing the controllable growth of device structures such as hetero junction, quantum well and superlattice, etc.

The invention discloses a method for preparing an anhydrous lithium iodide, comprising the following operation steps of: dehydrating the lithium iodide water solution to the lithium iodide powders containing 0.5-1 crystal water; and subsequently carrying out heating and dehydration treatment in vacuum to obtain the anhydrous lithium iodide. The invention also discloses a method for preparing a scintillation crystal doped with the lithium iodide, comprising the following operation steps of: dehydrating the lithium iodide water solution to the lithium iodide powders containing 0.5-1 crystal water; mixing the lithium iodide powder with the doped compound; subsequently carrying out heating and dehydration treatment in vacuum; and subsequently carrying out crystal growth under a vacuum state by adopting a Bridgman method, thus obtaining the scintillation crystal doped with the lithium iodide. The method for preparing the anhydrous lithium iodide has simple operation and no environmental pollution and is easy for large-scale industrial production; the method for preparing the scintillation crystal doped with the lithium iodide has simple process, is not easy to be oxidized at high temperature during the preparation process and can produce the high-quality scintillation crystal doped with the lithium iodide in batches.

The invention provides a growth device of an infrared crystal of polynary compounds and comprises a stove, a hearth box inside the stove comprises three temperature regions of an upper high-temperature region, a middle gradient region and a lower low-temperature region from up to down, a heater with standalone temperature control is respectively arranged inside the upper high-temperature region and the lower low-temperature region, a thermocouple with temperature control is respectively positioned inside the upper high-temperature region and the lower low-temperature region, and the middle gradient region is a heat-insulating and fireproof layer with ventholes; a loading rod that is used for loading a crucible pot of crystal growth is arranged inside the hearth box, a lower end of the loading rod is connected with a rotary clamping head that is connected with an electric motor, and the electric motor is arranged on a spiral travel mechanism. The growth device can obtain temperature fields that are suitable for crystal growth according to the growth habits of different infrared crystals of polynary compounds, maintains the stability of a solid-liquid interface and realizes the crystal growth in the planar interface. By using the growth device and adopting the Bridgman method, the infrared crystal of polynary compounds with complete appearance and well crystal property can be prepared.

The invention discloses a preparing method of high resistivity cadmium zinc telluride crystal. The method is characterized by comprising the following steps: according to stoichiometric ratio, the material which satisfies Cd0.9Zn0.1Te and the purity of which is 99.99999 percent are put in the inside of a super pure silica pot, and excessive Te with the mass percent of 0.5 percent to 2 percent and In with the volume concentration of (1-6) multiplied by 10<18>cm<-3> are added in the pot; the inside of the silica pot is vacuum-pumped and sealed; the silica pot is put in a synthesis furnace to synthesize raw materials; the pot is put in a five-section crystal growth furnace to grow crystal by the descending vertical Bridgman method. The method adopts the five-section normal pressure single crystal growth furnace and excessive Te is added in the crystal growth process, therefore the method provides enough deep level TeCd<2 plus> for the growth of Cd1-xZnxTe crystal, reduces production cost and obtains stable Cd1-xZnxTe crystal with high resistivity. At the same time, the partition ratio of In in Cd0.9Zn0.1Te crystal ingot approaches 1, thus causing the resistivity change of Cd0.9Zn0.1Te crystal ingot less and improving the uniformity and utilization rate of Cd0.9Zn0.1Te crystal.

The invention provides an improved gradient freeze GaAs single crystal growing method. According to the method, a traditional vertical gradient freeze (VGF) or vertical Bridgman (VB) crystal growing device is improved. The improved gradient freeze GaAs single crystal growing method is characterized in that a heating system is installed at the top of a crystal growing furnace and heating elements are a set of series-connection U-shaped silicomolybdic bars. The distribution curve of temperatures in a furnace body is formed through a heat insulation plate. GaAs raw materials are molten in a high-temperature area above the heat insulation plate and melt grows in a crystallizing mode in a temperature gradient area formed by the heat insulation plate. Obtained crystals are moved to the space below the heat insulation plate through a descending device, and high-temperature in-situ annealing is conducted to release thermal stress. GaAs single crystals grown by the adoption of the technology have the advantages of being low in dislocation, large in size, small in thermal stress and the like.

The invention discloses a <, a 100>, an axial orientation Fe-Ga magnetostriction material and the preparation method thereof. The material composites are Fe1-x-yGaxAly; wherein, x is between 16 per cent and 21 per cent or 25 per cent and 28 per cent; y is between 0 per cent and 10 per cent; the rest part is iron. The preparation method is that the raw material is melted under the protection of the inert gas, and the improved percy williams bridgman method is adopted to prepare the Fe-Ga magnetostriction material through the directional solidification; The heat treatment conditions are that the material is preserved at 1100 DEG C. to 1200 DEG C. for 0.5 hours to 24 hours, cooled with the furnace till 900 DEG C. to 750 DEG C. for 0.5 hours to 24 hours temperature preservation and then quenched or cooled by air to room temperature; or the material is preserved at 1100 DEG C. to 1200 DEG C. temperature for 0.5 hours to 24 hours and is cooled with the furnace till 500 to 700 DEG C..

A simulation optimization method of fuzzy control variable heating temperatures in a directional solidification process belongs to the material processing technical field. The simulation optimization method of the fuzzy control variable heating temperatures in the directional solidification process is characterized in that analog simulation is performed on the directional solidification process of the Bridgman method to simulate a temperature field evolution process of high temperature liquid metal in the directional solidification process; simultaneously temperature field simulation results in the directional solidification process serve as a guide of the simulation optimization method, a temperature setting value and time of duration of a heater need to change are determined by considering standard requirements of the industry to the directional solidification production of columnar and single crystal blades and utilizing a fuzzy control principle and algorithm to optimize a heater temperature changing process in the directional solidification process; and a temperature changing response value and time of duration of the heater are determined by utilizing a minimum sampling period under the precondition of reasonable simulated computation to obtain a process curve of the variable heater temperatures in the directional solidification process. The simulation optimization method of the fuzzy control variable heating temperatures in the directional solidification process has the advantages of improving the qualified rate of the directional and single crystal blade production, improving the production efficiency, reducing the process debugging period, upgrading the constant heater temperature process of the directional solidification production to the fuzzy control variable heating temperature process and being wide in application prospect.

The invention discloses a preparation method of a doped single crystal SnSe. The method comprises the following steps: sealing prepared raw materials into a quartz tube and putting the quartz tube into a furnace with a temperature gradient; raising a furnace temperature to a certain temperature; keeping the heat at the temperature for a period of time and sufficiently fusing the raw materials; and slowly crystallizing the fused raw materials from one end by adopting a Bridgman method and utilizing the temperature gradient in the furnace and a relative position change between a furnace cavity and the raw materials, so as to finally prepare the doped SnSe single crystal. The doped SnSe single crystal prepared by the invention is large in size and excellent in thermoelectric performance; a low-temperature-region ZT value is improved by near one order of magnitude relative to an undoped sample; and the preparation method has the advantages of low raw material cost and environmental friendliness so that the preparation method has a very good actual application prospect.

The invention discloses a compound SrCdGeS4 and a preparation method thereof, and an infrared nonlinear optical crystal as well as a preparation method and application thereof. A SrCdGeS4 compound pure phase is prepared by adopting a high-temperature solid-phase reaction method through two times of sintering, and the infrared nonlinear optical crystal grows by adopting a horizontal gradient condensation method or a Bridgman method. According to the method disclosed by the invention, the crystal easily grows and has relatively high quality; and the method the advantages of relatively high growth speed, low cost and easiness of obtaining crystals with relatively large sizes. An infrared nonlinear powder frequency doubling test shows that under the irradiation of fundamental frequency light which is 2090nm laser, the SrCdGeS4 has a very high nonlinear effect; and the frequency doubling signal intensity in a grain diameter range of 41mu m-74mu m is about three times of the signal intensity of an infrared classic material AgGaS2 with the same grain diameter. An infrared nonlinear optical crystal material SrCdGeS4 obtained by the invention has a potential application value in the field of infrared laser frequency conversion.

The invention discloses a novel inorganic compound photochromism material, a method for preparing the same and application thereof, and in particular relates to a photochromism material, a method for preparing the same and application thereof. The compound of the photochromism material has a chemical formula of Hg2AsCl2 which is a monoclinic system, the space group is C2/m(No.12), and the unicellular parameters comprise that: a is equal to between 13.6 and 14.3, b is equal to between 7.9 and 8.5, c is equal to between 8.5 and 9.3, alpha is equal to gamma which is equal to 90 degrees, beta is equal to between 94 and 101, and Z is equal to 8. After discoloration, the structure of the photochromism material is the monoclinic system, the space group is C2/m(No.12), and the unicellular parameters comprise that: a is equal to between 7.4 and 8.1, b is equal to between 7.9 and 8.5, c is equal to between 8.5 and 9.3, beta is equal to between 113 and 120, and Z is equal to 4. A compound, a monocrystal and a film material of the photochromism material are obtained by a vacuum high-temperature solid-phase synthesizing method, a Bridgman method and a vacuum heat vapor deposition method. The compound can be used for optical information storage, anti-counterfeit, laser protection, phase variation memory storage units, optical switches, optical information converters, self-development holographic recording photography, radiation quantifier and the like.

The invention provides a single crystal LiGa3Te5 which is in a non-centrosymmetric structure, belonging to a trigonal system; the space group is R32, and the cell parameters are as follows: alpha=beta=90 degrees, gamma=120 degrees, and Z=12; and the unit cell volume is expressed as follows: the diameter is 3-15mm, and the length is 20-40mm. The preparation method of the single crystal LiGa3Te5 comprises the steps of firstly preparing polycrystalline LiGa3Te5 and then growing the single crystal LiGa3Te5 by Bridgman method. The prepared single crystal LiGa3Te5 can be used for the physical performance test and the device research of crystals and is large enough; meanwhile, the single crystal LiGa3Te5 has a wide infrared transmission range and can realize mid and far infrared laser outputs by a nonlinear frequency transform technique so that the single crystal LiGa3Te5 can be applied to the manufacturing of nonlinear infrared optical devices as well as piezoelectric devices.

The invention provides the bridgman growing method for the growth of Ti3O5 crystal, which include that (1) the raw materials TiO2 and Ti are in proportioning according to Ti3O5 and mixed evenly, pressed. (2) The raw briquetting is loaded in a crucible that then transferred to the inside of a high-temperature decreasing furnace. The whole system is in heating pumping to 10-3-10-4Pa. When the furnace temperature reach 1400 to 1700 DEG degree, an insert protection gas is charged and the furnace is continuously heated to 1800 to 1900 DEG degree. (3) When the temperature reaches the set temperature, the heat is preserved for 3 to 6 hours so that the raw materials can be in full melting. The temperature gradient of solid-liquid interface for the crystal growth is within a framework of 20 to 60 DEG degree/cm, and the crucible decline rate is between 0.1 to 5.0mm/h. (4) After the end of the crystal growth, in an appropriate position inside the growing furnace, the heat is preserved for 10 to 24 hours. Afterwards, the furnace temperature is reduced to the room temperature with the speed of 25 to 80 DEG degree/h. The annealing treatment is implemented for the growing crystals.

The invention relates to a thermal control Bridgman method single crystal growth device and method for fluoride single crystals. A furnace body system is provided with a furnace cavity, a furnace bottom plate with a hole in the center, and a vacuum pipeline communicated with the furnace cavity, the hole in the center of the furnace bottom plate is communicated with a cavity body of the furnace cavity, the furnace cavity and the furnace bottom plate are both of a double-layer structure, and cooling water channels are distributed in interlayers. A heating and heat preservation system is arranged in the furnace cavity and provided with a heat insulation plate, heaters located on the upper side and the lower side of the heat insulation plate respectively and heat preservation screens located on the upper side and the lower side of the heat insulation plate respectively, and three temperature zones including the upper high temperature zone, the middle gradient zone and the lower low temperature zone are formed through the heat insulation plate. A crucible descending system comprises a crucible water cooling supporting pillar and a crucible descending transmission device, the lower end of the crucible water cooling supporting pillar is connected with the crucible descending transmission device, the upper end of the crucible water cooling supporting pillar penetrates through the hole in the center of the furnace bottom plate and stretches into the furnace cavity to support a crucible bracket, cooling water circulates in the crucible water cooling supporting pillar, and the flow and temperature of the cooling water in the crucible water cooling supporting pillar can be independently regulated and controlled in real time.

The invention discloses a vertical temperature grade kyropoulos method for growing large-size high-temperature oxide crystals, and relates to a novel process for crystal growth. On the basis of a kyropoulos method, the advantages of a Czochralski method (CZ), a heat exchange method (HEM), a temperature grade method (TGT) and a Bridgman method are combined, and equipment comprises a pulling structure, wherein the lower part of the pulling structure is connected with a furnace cover and a hearth; a flange seat, a metal heating body, a heat-insulating cover and a crucible are arranged in the hearth; an annular combined heat-insulating cover is fixed on the lower part of the flange seat; a crucible support and a crucible supporting rod for supporting the crucible are arranged below the crucible; and the heat-insulating cover covers the crucible supporting rod. By creating a special high-temperature vacuum crystal furnace capable of adjusting the temperature grade and the center of a temperature field, the large-size high-temperature oxide crystals are produced. The method has the advantage that: various high-quality high-temperature oxide crystal materials are manufactured at the lowest energy consumption and the lowest cost.

The invention relates to a gradient type temperature field heating element, in particular to a heating element which is applied in a crystal growing furnace and can effectively build an appropriate temperature gradient field, and the heating element belongs to the crystallization process technique field, and is mainly characterized in that a plurality of heating sheets with certain longitudinal-sectional and cross-sectional shapes are combined together reasonably to form one or a plurality of current paths, so as to produce different quantities of heat at parts with different resistance values, thereby certain temperature gradients can be produced in a growing zone; and the distribution of the temperature field can be adjusted flexibly through adjusting the cross-sectional shapes and heights of the heating sheets, The heating element only need one set of temperature control device when being used in the crystal growing furnace, thereby simplifying the operation, reducing the cost and also being favorable for keeping the stability of the temperature field, and the heating element is particularly applicable for crystal growing furnaces adopting descent methods, temperature gradient methods, resistance heating crystal pulling methods, Bridgman methods and heat exchange methods, and is also applied to other heat treatment devices needing the temperature gradient distribution.

This invention relates to a method for preparing heterovalent ions-doped high-luminescence-yield lead tungstate crystal and its preparation method. The high-luminescence-yield lead tungstate crystal is doped with F- 100-8000 ppm, Sb3+ 100-5000 ppm, and Mo6+, V5+, Nb5+, Zr4+, and Ti4+ 0-10000 ppm, and is prepared via modified Bridgman method by using platinum crucible. The method can be used for preparing several strands of lead tungstate crystals in one process, and is suitable for mass production. The obtained heterovalent ions-doped high-luminescence-yield lead tungstate crystal has such advantages as rapid attenuation and high luminescence yield.

The invention discloses a growing method of a magnesium fluoride barium single crystal, which comprises the following steps of firstly fluorating mixed powder of barium fluoride (BaF2) and magnesium fluoride (MgF2) or BaMgF4 powder; placing powder after fluoration and a seed crystal into a platinum crucible, enabling the crucible to be airtight; and then placing the platinum crucible into a single crystal furnace, and growing the magnesium fluoride barium single crystal by means of a bridgman method. The growing method of the magnesium fluoride barium single crystal has the advantages that a temperature field is stable, no CF4 gas is needed to be introduced in the growing process, the grown BaMgF4 single crystal is good in integrity and free of macro and micro defects, the rate of finished products is high, the size and the shape of the crystal are easily controlled, and the crystal is not easy to craze. In addition, the growing method is simple in processing equipment, convenient in operation, capable of remarkably reducing energy consumption and favorable for achieving industrial production.

The present invention relates to a large-sized and high-quality bismuth-zinc-borate (Bi.sub.2 ZnB.sub.2 O.sub.7) single crystal, preparation methods and applications thereof. The crystal has cross-sectional dimensions greater than one centimeter, a nonlinear optical effect of about 3-4 times that of KH.sub.2 PO.sub.4 (KDP), and an optical transmission wavelength range of 330-3300 nm. The crystal can be grown from a compound melt by a Czochralski method, a Kyropoulos method or a Bridgman method with the raw material being the synthetic compound Bi.sub.2 ZnB.sub.2 O.sub.7. Alternatively, the crystal may be grown from a high-temperature solution method by using Bi.sub.2 O.sub.3 as a flux. The crystal may be applied in nonlinear optical devices such as frequency doubling generators, frequency upconverters or downconverters, and optical parametric oscillators.

The invention discloses a growth method of gallium oxide crystals, which is a horizontal Bridgman method and specifically comprises the following steps: (1) putting gallium and gallium oxide into a crucible, and putting gallium oxide seed crystals into a seed crystal tank of the crucible; (2) putting the crucible into a growth furnace, vacuumizing the growth furnace, introducing inert gas, and heating the crucible to melt gallium oxide, so that the gallium oxide melt is in contact with the seed crystal; (3) after the gallium oxide is completely melted, sequentially carrying out crystal growthprocesses of seed introducing, shoulder forming and isometric growth; and (4) after the crystal growth is finished, cooling the crystal, and taking out the gallium oxide crystal. According to the invention, gallium and gallium oxide are put into the crucible, and gallium oxide floats on a gallium solution and is separated from the crucible in the crystal growth process, so that generated crystalsare prevented from being adhered to the crucible, the quality of the crystals is improved, and the crystals are easy to take out. Due to the existence of gallium, oxygen released in the growth processof the gallium oxide crystal can be absorbed to generate gallium oxide, impurities cannot be introduced, and the crucible is protected from being oxidized.