阅读说明：本技术 一种非静压条件下金属化的碲化锗制备及标定方法 (Preparation and calibration method of metalized germanium telluride under non-static pressure condition ) 是由 代立东 胡海英 于 2021-09-16 设计创作，主要内容包括：本发明公开了一种非静压条件下金属化的碲化锗制备及标定方法,分别在四柱型压机上下支撑块的合金钢和铍铜上开对称的圆孔；把金刚石置于安放在工装上的碳化钨底座上；将合金刚石下部与碳化钨底座固定；烘烤完后分别把两组金刚石和底座置于四柱型金刚石压腔高温高压实验设备上；预压T301不锈钢金属垫片；将将氮化硼和环氧树脂绝缘粉置入样品腔合上压机进行二次预压,将第二次预压后垫片样品腔用激光打孔机在中心钻出圆孔作为样品腔；将高纯度固体半导体碲化锗粉末作为初始物放入样品腔合上压机；加压至36.5GPa,并恒压3.0小时得到金属化的碲化锗；解决了现有技术制备金属相的碲化锗压力点不明确,标定不准确等技术问题。(The invention discloses a preparation and calibration method of metallized germanium telluride under a non-static pressure condition, which is characterized in that symmetrical round holes are respectively formed in alloy steel and beryllium copper of upper and lower supporting blocks of a four-column press; placing the diamond on a tungsten carbide base arranged on a tool; fixing the lower part of the alloy diamond with a tungsten carbide base; after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment; prepressing a T301 stainless steel metal gasket; placing boron nitride and epoxy resin insulating powder into a sample cavity, closing a press machine for secondary prepressing, and drilling a circular hole in the center of the gasket sample cavity after the secondary prepressing by using a laser drilling machine to serve as a sample cavity; putting high-purity solid semiconductor germanium telluride powder as an initial substance into a sample cavity closing press; pressurizing to 36.5GPa and keeping constant pressure for 3.0 hours to obtain metalized germanium telluride; the method solves the technical problems of unclear pressure point, inaccurate calibration and the like of the germanium telluride for preparing the metal phase in the prior art.)

1. A method for preparing metallized germanium telluride under non-hydrostatic pressure conditions, comprising:

step 1, respectively forming symmetrical round holes in alloy steel and beryllium copper of upper and lower supporting blocks of a four-column press;

step 2, soaking the diamond and the tungsten carbide base in acetone, ultrasonically cleaning the diamond and the tungsten carbide base for 25 minutes, and then placing the cleaned diamond on the tungsten carbide base placed on the tool;

fixing the lower part of the alloy diamond with a tungsten carbide base, placing the whole tool into an oven after two groups of diamonds and the tungsten carbide base are bonded, and baking and fusing the whole tool into a whole;

step 4, after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment;

step 5, prepressing the T301 stainless steel metal gasket to a thickness of 41 microns, and then drilling a round hole with the diameter of 145 microns at the center of the gasket by using a laser drilling machine to serve as a sample cavity;

step 6, horizontally placing a T301 stainless steel metal gasket between two diamonds of the four-column diamond pressure cavity high-temperature high-pressure experimental equipment, and placing boron nitride and epoxy resin insulating powder which are mixed in advance according to a ratio of 10:1 into a sample cavity;

step 7, closing a pressing machine, boosting the pressure to 10GPa, performing secondary pre-pressing, and maintaining the pressure for 5 minutes to completely solidify the insulating powder;

step 8, drilling a round hole with the diameter of 100 microns at the center of the T301 stainless steel metal gasket sample cavity subjected to the second pre-pressing by using a laser drilling machine to serve as a sample cavity;

step 9, horizontally placing a T301 stainless steel metal gasket between two diamonds of the self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, putting high-purity solid semiconductor germanium telluride powder serving as an initial material into a round hole sample cavity with the diameter of 100 mu m, and closing a press;

step 10, increasing pressure at a pressurizing rate of 15 GPa/h, extruding the sample cavity through two diamonds to generate high pressure, pressurizing to 36.5GPa, and keeping constant pressure for 3.0 hours;

and 11, releasing the pressure to normal pressure at the rate of 10 GPa/h, and taking out an experimental sample to obtain the metalized germanium telluride.

2. A method of producing germanium telluride metallized under non-hydrostatic conditions as claimed in claim 1 wherein: 1, opening symmetrical round holes with the diameter of 1.0mm on alloy steel and beryllium copper of a support block on a four-column press; and carrying out magnetron sputtering on the surface of the round hole to form alumina film insulating powder.

3. A method of producing germanium telluride metallized under non-hydrostatic conditions as claimed in claim 1 wherein: 2, after the diamond is placed on a tungsten carbide base arranged on a tool, finely adjusting the tungsten carbide base under a metallographic stage Olympus microscope to enable the diamond to be superposed with the center of the tungsten carbide base; another set of diamond and tungsten carbide mounts was mounted in the same step.

4. A method of producing germanium telluride metallized under non-hydrostatic conditions as claimed in claim 1 wherein: and 3, fixing the lower part of the alloy diamond with the tungsten carbide base, placing the whole tool into an oven after adhering two groups of diamonds and the tungsten carbide base, and baking and fusing the whole tool into a whole, wherein the method comprises the following steps: uniformly mixing the high-temperature industrial mending agent in a chip or glass bowl by using toothpicks to form a sticky state, and bonding the lower part of the diamond and the base by using the toothpicks to fix the high-temperature industrial mending agent after the high-temperature industrial mending agent is well mixed; after two groups of diamonds and the tungsten carbide base are bonded, the whole tool is placed in an oven to be baked at the baking temperature of 120 ℃ for 3 hours, so that the diamond anvil cell is firmly fixed on the tungsten carbide base through a high-temperature repairing agent and is fused into a whole.

5. A method of producing germanium telluride metallized under non-hydrostatic conditions as claimed in claim 1 wherein: and 4, after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment, wherein the plane of the four-column type diamond pressure cavity high-temperature high-pressure experimental equipment for placing the base needs to be kept clean, and diamond leveling and centering are carried out under a digital microscope, so that the anvil surfaces of the upper diamond and the lower diamond are completely superposed together.

6. A method of producing germanium telluride metallized under non-hydrostatic conditions as claimed in claim 1 wherein: the diamond anvil cell is directly used as a pressure mark for pressure calibration, and the accurate pressure calibration in the sample cavity is carried out through the result of the diamond Raman spectrum.

7. A calibration method of metalized germanium telluride under a non-static pressure condition is characterized by comprising the following steps: it includes:

step 1, respectively forming symmetrical round holes in alloy steel and beryllium copper of upper and lower supporting blocks of a four-column press;

step 2, soaking the diamond and the tungsten carbide base in acetone, ultrasonically cleaning the diamond and the tungsten carbide base for 25 minutes, and then placing the cleaned diamond on the tungsten carbide base placed on the tool;

fixing the lower part of the alloy diamond with a tungsten carbide base, placing the whole tool into an oven after two groups of diamonds and the tungsten carbide base are bonded, and baking and fusing the whole tool into a whole;

step 4, after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment;

step 5, prepressing the T301 stainless steel metal gasket to a thickness of 39 μm, and then drilling a round hole with a diameter of 151 μm in the center of the gasket by using a laser puncher to serve as a sample cavity;

step 6, adding boron nitride and epoxy resin insulating powder which are mixed according to a ratio of 10:1 into a sample cavity;

step 7, closing the press, boosting the pressure to 10GPa, performing secondary pre-pressing, and maintaining the pressure for 5 minutes to completely solidify the insulating powder;

step 8, drilling a round hole with the diameter of 100 microns in the center of the T301 stainless steel metal gasket sample cavity subjected to the second pre-pressing by using a laser drilling machine;

step 9, horizontally placing the T301 stainless steel metal gasket with the drilled holes of 100 microns between two diamonds of a four-column diamond pressure cavity high-temperature high-pressure experimental device, and putting high-purity solid semiconductor germanium telluride powder serving as an initial material into a circular hole with the diameter of 100 microns to be closed by a pressing machine;

step 10, a metal platinum wire with the thickness of 4 microns is used as an electrode, and a platinum electrode required by conductivity measurement is accurately placed to the upper and lower parts of a sample under a metallographic Olympus microscope; leading out electrode leads from circular holes of alloy steel and beryllium copper of an upper supporting block and a lower supporting block of a four-column press;

step 11, calibrating the temperature of the sample cavity by using a K-type thermocouple, and leading out the thermocouple from circular holes of alloy steel and beryllium copper of a lower supporting block of the self-improved four-column press; carrying out magnetron sputtering on the surface of the round hole with alumina film insulating powder;

step 12, connecting the assembled electrode lead of the experimental device with a Solartron-1260 impedance and gain phase analyzerThen, the voltage and the frequency of the induced polarization signal for in-situ measurement of the sample conductivity are set to be 1.0V and 10 respectively^-1To 10⁶Hz；

Step 13, measuring the electrochemical alternating-current impedance spectrum of the germanium telluride sample at a pressurizing rate of 10 GPa/h and pressure points at intervals of 2.0GPa, fitting the resistance of the sample by using ZView software, and applying a formula:

accurately calculating the conductivity of the germanium telluride sample under the condition of each given pressure point;

step 14, pressurizing to 36.5GPa, and obtaining a semiconductor conductivity value 10 from germanium telluride through conductivity under normal pressure^-4And judging the phase state transition of the phase change material germanium telluride metallization under the condition that the S/cm is 10S/cm of the sample metal phase under the condition of 36.5 GPa.

Technical Field

The invention belongs to the technical field of functional material synthesis, and particularly relates to a preparation and calibration method of metalized germanium telluride under a non-static pressure condition.

Background

Generally, a phase change material refers to a substance that provides latent heat by physical phase transition under a given temperature condition. The phase-change process is a phase-change process, and the material absorbs or releases a large amount of latent heat during the phase-change process. The phase-change material is an optimal green environment-friendly carrier with energy conservation and environmental protection, is an important functional material which is extremely concerned by a plurality of international scientific research institutes and research and development institutions, and has extremely wide application in human production activities and daily life. Germanium telluride (chemical formula: GeTe), which is one of the most typical important phase change materials, is composed of a cation of the 32 th element, germanium, which is a carbon group element (fourth group) in the periodic table, and an anion of the 52 nd element, tellurium, which is an chalcogen (sixth group). Germanium telluride is a semiconductor with a triangular face-centered structure at normal temperature and pressure, and has a relatively low band gap energy (0.23 eV). Because of the unique crystal structure of germanium telluride, the germanium telluride has wide application in erasable optical discs, erasable digital multifunctional optical discs, random access memories, blue-ray discs and the like.

The conductivity of the semiconductor is 1 × 10^-5S/cm to 0.1S/cm, and the metal conductivity is more than 0.1S/cm. Germanium telluride is a narrow energy gap semiconductor at normal temperature and normal pressure, and how to convert the germanium telluride into metal has very important application value. Metalized germanium telluride will exhibit properties distinct from semiconductor materials such as extremely high electron mobility, excellent flexibility and optical transparency. The flexible phase change material is expected to be developed into a small-size low-voltage flexible electronic device which is more energy-saving than the traditional phase change material. Therefore, the preparation of germanium telluride and the characterization of the unique physicochemical and optical properties thereof by technical means have great scientific significance and industrial value.

The preparation and calibration of the metal phase germanium telluride by adopting a high-pressure method at home and abroad mainly has the following three problems: 1. the sample preparation method comprises the following steps: the pressure point of the germanium telluride for preparing the metal phase is not clear, the pressure is too low, and the product which can be obtained is a mixture of a semiconductor phase and the metal phase instead of pure-phase germanium telluride; on the contrary, the pressure is too high, the cost is obviously increased, the preparation of the germanium telluride phase-change material with high purity and stable performance is not facilitated, and the industrial production is difficult to realize; 2. high-temperature high-pressure device that sample was markd: in the traditional high-temperature and high-pressure equipment adopting the piston cylinder type diamond anvil, as the sample cavity of the device is completely sealed, the device is not beneficial to leading out an electrical property measuring circuit, the problem of sample short circuit in the high-pressure conductivity measuring process is easily caused, and the device is not easy to be used for effectively calibrating the metallic materialization behavior of materials; 3. and (3) metallization identification: the traditional means such as synchrotron radiation X-ray diffraction, high-pressure Raman spectrum, first principle theoretical calculation and the like under the condition of high pressure (<25GPa) cannot effectively predict the possible metal phase transformation of the germanium telluride under the high pressure, and no effective method for carrying out system calibration on the metallization behavior of the zinc telluride of the metal phase exists at present.

The invention content is as follows:

the technical problem to be solved by the invention is as follows: the method is used for solving the problems that the pressure point of the germanium telluride for preparing the metal phase in the prior art is not clear, the pressure is too low, and the obtained product is a mixture of a semiconductor phase and the metal phase instead of pure-phase germanium telluride; on the contrary, the pressure is too high, the cost is obviously increased, the preparation of the germanium telluride phase-change material with high purity and stable performance is not facilitated, and the industrial production is difficult to realize; 2. the traditional high-temperature and high-pressure device for calibrating the sample adopts piston-cylinder type diamond anvil high-temperature and high-pressure equipment, and as the sample cavity of the device is completely sealed and is not beneficial to leading out an electrical property measuring circuit, the short-circuit problem of the sample in the high-pressure conductivity measuring process is easily caused, and the device is not easy to be used for effectively calibrating the metallic behavior of the material; 3. the metallization identification adopts means such as synchrotron radiation X-ray diffraction under the condition of high pressure (<25GPa), high-pressure Raman spectroscopy, first principle theoretical calculation and the like, so that the possibility of metal phase transformation of germanium telluride under high pressure cannot be effectively predicted, and no effective method for carrying out system calibration on the metallization behavior of zinc telluride of a metal phase exists at present.

The technical scheme of the invention is as follows:

a method for preparing metallized germanium telluride under non-hydrostatic pressure conditions, comprising:

step 1, respectively forming symmetrical round holes in alloy steel and beryllium copper of upper and lower supporting blocks of a four-column press;

step 2, soaking the diamond and the tungsten carbide base in acetone, ultrasonically cleaning the diamond and the tungsten carbide base for 25 minutes, and then placing the cleaned diamond on the tungsten carbide base placed on the tool;

fixing the lower part of the alloy diamond with a tungsten carbide base, placing the whole tool into an oven after two groups of diamonds and the tungsten carbide base are bonded, and baking and fusing the whole tool into a whole;

step 4, after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment;

step 5, prepressing the T301 stainless steel metal gasket to a thickness of 41 microns, and then drilling a round hole with the diameter of 145 microns at the center of the gasket by using a laser drilling machine to serve as a sample cavity;

step 6, horizontally placing a T301 stainless steel metal gasket between two diamonds of the four-column diamond pressure cavity high-temperature high-pressure experimental equipment, and placing boron nitride and epoxy resin insulating powder which are mixed in advance according to a ratio of 10:1 into a sample cavity;

step 7, closing a pressing machine, boosting the pressure to 10GPa, performing secondary pre-pressing, and maintaining the pressure for 5 minutes to completely solidify the insulating powder;

step 8, drilling a round hole with the diameter of 100 microns at the center of the T301 stainless steel metal gasket sample cavity subjected to the second pre-pressing by using a laser drilling machine to serve as a sample cavity;

step 9, horizontally placing a T301 stainless steel metal gasket between two diamonds of the self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, putting high-purity solid semiconductor germanium telluride powder serving as an initial material into a round hole sample cavity with the diameter of 100 mu m, and closing a press;

step 10, increasing pressure at a pressurizing rate of 15 GPa/h, extruding the sample cavity through two diamonds to generate high pressure, pressurizing to 36.5GPa, and keeping constant pressure for 3.0 hours;

and 11, releasing the pressure to normal pressure at the rate of 10 GPa/h, and taking out an experimental sample to obtain the metalized germanium telluride.

1, opening symmetrical round holes with the diameter of 1.0mm on alloy steel and beryllium copper of a support block on a four-column press; and carrying out magnetron sputtering on the surface of the round hole to form alumina film insulating powder.

2, after the diamond is placed on a tungsten carbide base arranged on a tool, finely adjusting the tungsten carbide base under a metallographic stage Olympus microscope to enable the diamond to be superposed with the center of the tungsten carbide base; another set of diamond and tungsten carbide mounts was mounted in the same step.

And 3, fixing the lower part of the alloy diamond with the tungsten carbide base, placing the whole tool into an oven after adhering two groups of diamonds and the tungsten carbide base, and baking and fusing the whole tool into a whole, wherein the method comprises the following steps: uniformly mixing the high-temperature industrial mending agent in a chip or glass bowl by using toothpicks to form a sticky state, and bonding the lower part of the diamond and the base by using the toothpicks to fix the high-temperature industrial mending agent after the high-temperature industrial mending agent is well mixed; after two groups of diamonds and the tungsten carbide base are bonded, the whole tool is placed in an oven to be baked at the baking temperature of 120 ℃ for 3 hours, so that the diamond anvil cell is firmly fixed on the tungsten carbide base through a high-temperature repairing agent and is fused into a whole.

And 4, after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment, wherein the plane of the four-column type diamond pressure cavity high-temperature high-pressure experimental equipment for placing the base needs to be kept clean, and diamond leveling and centering are carried out under a digital microscope, so that the anvil surfaces of the upper diamond and the lower diamond are completely superposed together.

The diamond anvil cell is directly used as a pressure mark for pressure calibration, and the accurate pressure calibration in the sample cavity is carried out through the result of the diamond Raman spectrum.

A method for calibrating metalized germanium telluride under a non-hydrostatic condition comprises the following steps:

step 1, respectively forming symmetrical round holes in alloy steel and beryllium copper of upper and lower supporting blocks of a four-column press;

step 2, soaking the diamond and the tungsten carbide base in acetone, ultrasonically cleaning the diamond and the tungsten carbide base for 25 minutes, and then placing the cleaned diamond on the tungsten carbide base placed on the tool;

fixing the lower part of the alloy diamond with a tungsten carbide base, placing the whole tool into an oven after two groups of diamonds and the tungsten carbide base are bonded, and baking and fusing the whole tool into a whole;

step 4, after baking, respectively placing the two groups of diamonds and the base on four-column type diamond pressure cavity high-temperature high-pressure experimental equipment;

step 5, prepressing the T301 stainless steel metal gasket to a thickness of 39 μm, and then drilling a round hole with a diameter of 151 μm in the center of the gasket by using a laser puncher to serve as a sample cavity;

step 6, adding boron nitride and epoxy resin insulating powder which are mixed according to a ratio of 10:1 into a sample cavity;

step 7, closing the press, boosting the pressure to 10GPa, performing secondary pre-pressing, and maintaining the pressure for 5 minutes to completely solidify the insulating powder;

step 8, drilling a round hole with the diameter of 100 microns in the center of the T301 stainless steel metal gasket sample cavity subjected to the second pre-pressing by using a laser drilling machine;

step 9, horizontally placing the T301 stainless steel metal gasket with the drilled holes of 100 microns between two diamonds of a four-column diamond pressure cavity high-temperature high-pressure experimental device, and putting high-purity solid semiconductor germanium telluride powder serving as an initial material into a circular hole with the diameter of 100 microns to be closed by a pressing machine;

step 10, a metal platinum wire with the thickness of 4 microns is used as an electrode, and a platinum electrode required by conductivity measurement is accurately placed to the upper and lower parts of a sample under a metallographic Olympus microscope; leading out electrode leads from circular holes of alloy steel and beryllium copper of an upper supporting block and a lower supporting block of a four-column press;

step 11, calibrating the temperature of the sample cavity by using a K-type thermocouple, and leading out the thermocouple from circular holes of alloy steel and beryllium copper of a lower supporting block of the self-improved four-column press; carrying out magnetron sputtering on the surface of the round hole with alumina film insulating powder;

step 12, connecting the electrode lead of the assembled experimental device with a Solartron-1260 impedance and gain phase analyzer, and setting the induced polarization signal voltage and the signal frequency of the sample conductivity in-situ measurement to be 1.0V and 10V respectively^-1To 10⁶Hz；

Step 13, measuring the electrochemical alternating-current impedance spectrum of the germanium telluride sample at a pressurizing rate of 10 GPa/h and pressure points at intervals of 2.0GPa, fitting the resistance of the sample by using ZView software, and applying a formula:

accurately calculating the conductivity of the germanium telluride sample under the condition of each given pressure point;

step 14, pressurizing to 36.5GPa, and obtaining a semiconductor conductivity value 10 from germanium telluride through conductivity under normal pressure^-4And judging the phase state transition of the phase change material germanium telluride metallization under the condition that the S/cm is 10S/cm of the sample metal phase under the condition of 36.5 GPa.

The invention has the beneficial effects that:

according to the invention, the high-purity germanium telluride phase change material with stable performance is synthesized on the independently improved four-column type diamond pressure cavity high-temperature high-pressure experimental equipment under the conditions of non-hydrostatic pressure and 36.5 GPa; by comparing the conductivity measurement results under high pressure (pressure range: 0.5-36.5GPa) in detail, the conversion of a sample from a semiconductor to metal is effectively detected, and a set of most direct, accurate and efficient new calibration method for compounds with AB structures aiming at equal germanium telluride metals under non-hydrostatic pressure conditions is worked out.

In order to overcome the defects of the traditional diamond anvil cell high-temperature high-pressure experimental equipment, the invention adopts the self-improved four-column type diamond pressure cavity high-temperature high-pressure experimental equipment to synthesize the high-purity and stable-performance germanium telluride phase change material under the conditions of non-pure water pressure, room temperature and 36.5GPa, so that the recovered sample has excellent flexibility and high optical transmittance, and the application of the material to industrial production and wide application is realized;

compared with the traditional piston-cylinder type diamond press, the press has the superior characteristics of strong stability, large space size of a sample cavity, capability of realizing higher experimental pressure and the like, the sample cavity is not completely sealed, a conductivity measurement circuit of a germanium telluride sample is easily led out, good insulativity is effectively realized in the process of measuring the electrical properties of a semiconductor material, and the autonomously improved four-cylinder type diamond press high-temperature high-pressure experimental equipment can be completely applied to effective calibration of the metallicity behavior of a phase change material;

the invention adopts the most advanced method of conductivity measurement, namely an electrochemical alternating-current impedance spectroscopy, and can effectively judge the metallization behavior of the zinc telluride phase-change material caused by pressure through the conductivity value of the semiconductor zinc telluride phase-change material under the normal temperature and the normal pressure. The prepared metal phase germanium telluride phase-change material with high purity and stable performance is placed on self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, the sample conductivity is measured in situ at high pressure by adopting an electrochemical alternating-current impedance spectroscopy technology, the performance of the synthesized metal phase germanium telluride phase-change material is effectively evaluated from the conductivity value of the electromigration property, and the industrial production is effectively guided.

The problem that the pressure point of the germanium telluride for preparing the metal phase in the prior art is not clear, the pressure is too low, and the obtained product is a mixture of a semiconductor phase and the metal phase instead of pure-phase germanium telluride is solved; on the contrary, the pressure is too high, the cost is obviously increased, the preparation of the germanium telluride phase-change material with high purity and stable performance is not facilitated, and the industrial production is difficult to realize; 2. the traditional high-temperature and high-pressure device for calibrating the sample adopts piston-cylinder type diamond anvil high-temperature and high-pressure equipment, and as the sample cavity of the device is completely sealed and is not beneficial to leading out an electrical property measuring circuit, the short-circuit problem of the sample in the high-pressure conductivity measuring process is easily caused, and the device is not easy to be used for effectively calibrating the metallic behavior of the material; 3. the metallization identification adopts means such as synchrotron radiation X-ray diffraction under the condition of high pressure (<25GPa), high-pressure Raman spectroscopy, first principle theoretical calculation and the like, so that the possibility of metal phase transformation of germanium telluride under high pressure cannot be effectively predicted, and no effective method for carrying out system calibration on the metallization behavior of zinc telluride of a metal phase exists at present.

Description of the drawings:

FIG. 1 is a schematic view of the apparatus of the present invention;

in fig. 1, 1 is alloy steel, 2 is beryllium copper, 3 is a table, 4 is a press upper die, 5 is an upper die cylinder inner wall, 6 is a press lower die, 7 is a diamond anvil, 8 is a T301 stainless steel metal gasket, 9 is a K-type thermocouple, 10 is a platinum electrode and a lead wire of an upper anvil surface, 11 is a platinum electrode and a lead wire of a lower anvil surface, 12 is a sample, and 13 is a tungsten carbide base. Wherein 1-6 are external pressurizing devices, which aim to press the diamonds in the middle of the table by mechanical shaking, so that high pressure is generated at the opposite tops of the two diamonds. 7-13 are internal fixing and measuring devices; leads 10 and 11 are connected to a Solartron-1260 impedance analyzer for the purpose of measuring the impedance of the sample.

The specific implementation mode is as follows:

the invention discloses a preparation and calibration method of metalized germanium telluride of a typical phase-change material under a non-static pressure condition, which comprises the following steps: it includes:

1. high-pressure preparation:

(1) in order to meet the requirements of the invention, the invention adopts an autonomously improved four-column type press for experiments, the improved four-column type diamond pressing cavity high-temperature high-pressure experimental equipment is shown in figure 1, and the specific improvement scheme is that four symmetrical round holes (the hole diameter is 1.0mm) are respectively formed in the alloy steel and the beryllium copper of the upper supporting block and the lower supporting block of the original press so as to facilitate the leading-out of an electrode lead and a thermocouple lead in the experimental process, and the surface of the alloy steel and the beryllium copper is subjected to magnetron sputtering of alumina film insulating powder so as to facilitate the measurement of the circuit in the experimental process to have better insulation. Meanwhile, compared with the traditional piston-cylinder press, the improved four-column press has the superior characteristics of stronger stability, large space size of a sample cavity, capability of realizing higher experimental pressure and the like, and can be completely applied to effective calibration of phase-change material metallicity behavior;

(2) the diamond (with a 300-micron anvil surface) and the tungsten carbide base are soaked in acetone for 25 minutes by ultrasonic treatment, the diamond and the tungsten carbide base are completely cleaned, then the cleaned diamond is placed on the tungsten carbide base arranged on a tool, and the tungsten carbide base is finely adjusted under a high-power metallographic stage Olinbas microscope, so that the diamond and the tungsten carbide base are approximately superposed. Installing another group of diamond and tungsten carbide base in the same step;

(3) and taking a proper amount of the high-temperature industrial healant, uniformly mixing the proper amount of the high-temperature industrial healant in a chip or glass bowl by using toothpicks to form a sticky state, and bonding the lower part of the diamond and the base by using the toothpicks to fix the diamond after mixing. After two groups of diamonds and the tungsten carbide base are bonded, the whole tool is placed in an oven to be baked, the baking temperature is 120 ℃ and the duration time is 3 hours, so that the diamond anvil cell is firmly fixed on the tungsten carbide base through a high-temperature repairing agent and is fused into a whole;

(4) after baking, respectively placing the two groups of diamonds and the base on self-improved four-column type diamond pressure cavity high-temperature high-pressure experimental equipment, wherein the plane of the self-improved four-column type diamond pressure cavity high-temperature high-pressure experimental equipment for placing the base needs to be ensured to be clean, and diamond leveling and centering are carried out under a high-multiple microscope, so that the anvil surfaces of the upper diamond and the lower diamond are completely superposed together;

(5) according to the assembly shown in the figure 1, after the device is placed in self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, a T301 stainless steel gasket is pre-pressed, the pre-pressing thickness is 41 microns, and then a round hole with the diameter of 145 microns is drilled in the center of the gasket by using a laser drilling machine to serve as a sample cavity;

(6) the T301 stainless steel metal gasket after drilling is horizontally placed between two diamonds of self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, boron nitride and epoxy resin insulating powder which are mixed in advance according to a ratio of 10:1 are placed into a sample cavity, and the insulating powder in the ratio not only ensures that good insulating property is provided, but also is easy to solidify; the most important is that the hole wall of the stainless steel metal gasket can be separated from the solid semiconductor germanium telluride powder, so that the solid semiconductor germanium telluride powder is prevented from being secondarily polluted.

(7) After the boron nitride and epoxy resin insulating powder are placed in the sample cavity, a press is closed, the pressure is increased to 10GPa for secondary prepressing, and the pressure is maintained for 5 minutes, so that the insulating powder is completely solidified, and excellent insulating property is provided;

(8) drilling a round hole with the diameter of 100 mu m in the center of the T301 stainless steel metal gasket sample cavity subjected to the second pre-pressing by using a laser drilling machine;

(9) horizontally placing the T301 stainless steel metal gasket with the drilled 100 mu m hole between two diamonds of the self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, taking high-purity 99.999% solid semiconductor germanium telluride powder as an initial substance, and closing a press;

(10) in order to avoid sample pollution caused by the introduction of marking materials, the diamond anvil is directly used as a marking to carry out pressure marking; carrying out accurate pressure calibration in the sample cavity according to a diamond Raman spectrum result under high pressure;

(11) in order to avoid unnecessary product cost increase caused by diamond fracture in the pressurizing process, the pressurizing rate of 15 GPa/h is used for slowly increasing the pressure, the sample cavity is slowly squeezed by two diamonds to generate high pressure, the pressure is increased to 36.5GPa, and the pressure is kept constant for 3.0 hours, so that the phase transformation of the germanium telluride from a semiconductor to a metal is completely finished;

(12) in order to avoid unnecessary increase of product cost caused by diamond fracture in the pressurizing process, the pressure is released to normal pressure at the pressurizing rate of 10 GPa/h, and an experimental sample is carefully taken out under a high-magnification microscope;

(13) the experimental sample after pressure relief is observed by a high-resolution optical microscope, an atomic force microscope and a transmission electron microscope, and the obtained zinc telluride experimental sample has good metallic luster, excellent flexibility and high optical transmittance;

(14) in the whole preparation process of the metal phase germanium telluride, no pressure transmission medium such as silicone oil, sodium chloride and the like is introduced, the sample cavity is completely in a typical non-hydrostatic pressure environment, and the metal phase germanium telluride phase change material obtained under the high-pressure condition has the excellent performances of high purity, stable performance and the like.

2. The calibration method comprises the following steps:

the invention adopts the most advanced method of conductivity measurement, namely an electrochemical alternating-current impedance spectroscopy, and can effectively judge the metallization behavior of the zinc telluride phase-change material caused by pressure through the conductivity value of the semiconductor zinc telluride phase-change material under the normal temperature and the normal pressure.

The method for calibrating metalized germanium telluride by high-pressure conductivity comprises the following steps:

(1) in order to meet the requirements of the invention, an independently improved four-column type press is adopted for carrying out experiments, the improved four-column type diamond pressing cavity high-temperature high-pressure experimental equipment is shown in figure 1, and the specific improvement scheme is that four symmetrical round holes (the hole diameter is 1.0mm) are respectively formed in alloy steel and beryllium copper of an upper supporting block of an original press so as to facilitate the leading-out of an electrode lead and a thermocouple lead in the experimental process, and aluminum oxide film insulating powder is subjected to magnetron sputtering on the surface of the alloy steel and the beryllium copper so as to facilitate the measurement of a circuit in the experimental process to have better insulation. Meanwhile, compared with the traditional piston-cylinder press, the improved four-column press has the superior characteristics of stronger stability, large space size of a sample cavity, capability of realizing higher experimental pressure and the like, and can be completely applied to effective calibration of phase-change material metallicity behavior;

(2) the diamond (with a 300-micron anvil surface) and the tungsten carbide base are soaked in acetone for 40 minutes by ultrasonic treatment, the diamond and the tungsten carbide base are completely cleaned, then the cleaned diamond is placed on the tungsten carbide base arranged on a tool, and the tungsten carbide base is finely adjusted under a high-power metallographic stage Olinbas microscope, so that the diamond and the tungsten carbide base are approximately superposed. Installing another group of diamond and tungsten carbide base in the same step;

(3) and taking a proper amount of the high-temperature industrial healant, uniformly mixing the proper amount of the high-temperature industrial healant in a chip or glass bowl by using toothpicks to form a sticky state, and bonding the lower part of the diamond and the base by using the toothpicks to fix the diamond after mixing. After two groups of diamonds and the tungsten carbide base are bonded, the whole tool is placed in an oven to be baked, the baking temperature is 120 ℃ and the duration time is 3 hours, so that the diamond anvil cell is firmly fixed on the tungsten carbide base through a high-temperature repairing agent and is fused into a whole;

(4) after baking, respectively placing the two groups of diamonds and the base on self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, wherein the planes of the self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment for placing the base need to be kept clean, and leveling and centering of the diamonds are carried out under a high-multiple microscope, so that the two diamonds are completely positioned on the same horizontal plane;

(5) according to the assembly shown in the figure 1, after the device is placed in self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, a T301 stainless steel gasket is pre-pressed, the pre-pressing thickness is 39 mu m, and then a round hole with the diameter of 151 mu m is drilled in the center of the gasket by using a laser puncher to serve as a sample cavity;

(6) the T301 stainless steel metal gasket after drilling is horizontally placed between two diamonds of self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, and boron nitride and epoxy resin insulating powder which are mixed in advance according to a ratio of 10:1 are formed, wherein the insulating powder in the ratio not only ensures that good insulating property is provided, but also is easy to solidify;

(7) putting the powder into a sample cavity, closing a press, boosting the pressure to 10GPa, performing secondary pre-pressing, and maintaining the pressure for 5 minutes to completely solidify the insulating powder so as to provide excellent insulating property;

(8) drilling a round hole with the diameter of 100 mu m in the center of the T301 stainless steel metal gasket sample cavity subjected to the second pre-pressing by using a laser drilling machine;

(9) horizontally placing the T301 stainless steel metal gasket with the drilled 100 mu m hole between two diamonds of the self-improved four-column diamond pressure cavity high-temperature high-pressure experimental equipment, taking high-purity 99.999% solid semiconductor germanium telluride powder as an initial substance, and closing a press;

(10) according to the method shown in 10 and 11 in figure 1, a high-purity metal platinum wire with the thickness of 4 microns is used as an electrode, a platinum electrode required for conductivity measurement is accurately placed under a high-power metallographic-grade Olympus microscope, the platinum electrode is led out from circular holes (the hole diameter is 1.0mm) of alloy steel and beryllium copper of an upper supporting block and a lower supporting block of an independently improved four-column type press, a thermocouple lead of the improved press is easier to fix, and aluminum oxide film insulating powder is subjected to magnetron sputtering on the surface of the thermocouple lead, so that a circuit has better insulation in the conductivity measurement process.

(11) According to the method shown in 9 in figure 1, the temperature of a sample cavity is calibrated by a K-type thermocouple, the thermocouple is led out from a circular hole (the diameter of the hole is 1.0mm) of alloy steel and beryllium copper of a lower supporting block of an independently improved four-column type press, a thermocouple lead of the improved press is easier to fix, and alumina film insulating powder is subjected to magnetron sputtering on the surface of the thermocouple lead, so that a measuring line has better insulation in the temperature calibration process.

(12) In order to avoid sample pollution caused by the introduction of a marking material, the diamond anvil is directly used as a marking, and accurate pressure calibration in a sample cavity is carried out through a diamond Raman spectrum result under high pressure;

(13) As shown in the assembly of FIG. 1, the electrode leads 10 and 11 of the assembled experimental device are connected with a Solartron-1260 impedance/gain phase analyzer, and the induced polarization signal voltage and the signal frequency of the sample conductivity in-situ measurement are respectively set to be 1.0V and 10V^-1-10⁶Hz；

(14) In order to avoid the increase of product cost caused by diamond fracture in the pressurizing process, fully consider the transformation time of the germanium telluride phase from a semiconductor to metal and the time required by the impedance spectrum of a collected sample under each pressure point, measure the electrochemical alternating current impedance spectrum of the germanium telluride sample at the pressure points at the interval of 2.0GPa at the pressurizing rate of 10 GPa/h, fit the resistance of the sample by ZView software, and apply the formula:

accurately calculating the conductivity of the germanium telluride sample under the condition of each given pressure point;

(15) slowly pressurizing to 36.5GPa, and obtaining a semiconductor conductivity value of 10 from germanium telluride through conductivity at normal pressure^-4The phase state transition of the phase change material germanium telluride metallization can be effectively judged under the condition that the S/cm is 10S/cm of the sample metal phase under 36.5 GPa.