A metal hydride material and preparation method thereof

Abstract

The present invention discloses a metal hydride material and a preparation method thereof, which belongs to the technical field of energetic materials, and solves the problem that the hydrogen content in the metal hydride material prepared in the prior art is low and the method for preparing the metal hydride material requires a high pressure. The chemical formula of the metal hydride material is HfHn, and the value range of n is 3.75 to 18. The preparation method of the metal hydride material comprises the following steps: S1, encapsulating the hydrogen source material and the metal raw material into a high-pressure cavity; a catalyst is placed in the high-pressure cavity; S2, pressurizing the hydrogen source material and the metal raw material, and after reaching the target pressure, starting heating, and maintaining the pressure and heat to prepare the metal hydride material HfHn. The HfHn of the present invention has a high hydrogen content, which improves the energy density of the metal hydride material.

Description

Technical Field

[0001] The present invention belongs to the technical field of energetic materials, and in particular relates to a metal hydride material and a preparation method thereof. Background Art

[0002] With the progress of society and the development of science and technology, various application scenarios of weapons have put forward higher requirements for the safety, environmental protection and energy density of energetic materials. At present, the energy density of conventional energetic materials based on chemical energy such as carbon, hydrogen, nitrogen and oxygen has reached its limit, and it is urgent to find energetic materials with higher energy density. Solid hydrogen will be converted from an insulating state to a metallic state under high pressure conditions, which is called metallic hydrogen. The energy density of metallic hydrogen is about 218kJ / g, which is about 50 times the TNT equivalent; as a propellant, the theoretical specific impulse of metallic hydrogen is 1700s, which is 3.5 times the specific impulse of the most powerful propellant currently. Therefore, metallic hydrogen belongs to ultra-high energy density materials and is the commanding height of conventional damage energetic materials in the future.

[0003] Metallic hydrogen materials are mainly prepared by static high pressure. In 2017, a team from Harvard University reported the discovery of metallic hydrogen under a high pressure of 495 GPa. Unfortunately, the experiment was not recognized by the industry due to the lack of direct evidence and the failure to reproduce the samples. In 1977, Mr. Xu Jianan of the Institute of Physics of the Chinese Academy of Sciences published his research work on metallic hydrogen materials in the Journal of Physics, predicting some important properties of metallic hydrogen, and pioneeringly proposed to achieve the properties of metallic hydrogen by preparing hydrogen-containing crystals, that is, hydrogen-rich materials. In 2004, American scientists again proposed the idea of ​​preparing hydrogen-rich materials through chemical pre-pressing to achieve metallic hydrogen materials. At present, the industry generally believes that the synthesis of metallic hydrogen requires extremely high pressure, and it is a relatively ideal route to achieve the properties of metallic hydrogen by synthesizing hydrogen-rich materials.

[0004] In recent years, various types of metal hydride crystalline materials have been experimentally studied. However, the hydrogen content in metal hydrides is generally low, and how to obtain metal hydrides with higher hydrogen content is still an urgent problem to be solved. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide a metal hydride material and a method for preparing the same, so as to solve one of the following technical problems: (1) the method for preparing the metal hydride material in the prior art requires a high pressure and harsh conditions, which are not easy to achieve; (2) the hydrogen content in the metal hydride material prepared in the prior art is low.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions:

[0007] In one aspect, the present invention provides a metal hydride material, wherein the chemical formula of the metal hydride material is HfHn, and the value range of n is 3.75-18.

[0008] On the other hand, the present invention also provides a method for preparing a metal hydride material, comprising the following steps:

[0009] S1. Encapsulating hydrogen source materials and metal raw materials into a high-pressure cavity; a catalyst is placed in the high-pressure cavity;

[0010] S2. Pressurize the hydrogen source material and the metal raw material, and after reaching the target pressure, start heating, and maintain the pressure and temperature to prepare the metal hydride material HfHn, where the value of n is in the range of 3.75 to 18.

[0011] Furthermore, the catalyst includes an alkali metal, an alkaline earth metal, a transition metal or a lanthanide.

[0012] Further, the catalyst includes Li, Ca, Fe, Pd, Pt or Ce.

[0013] Furthermore, before S1, the step further includes: completing the preparation work of the diamond anvil cell, and the preparation work of the diamond anvil cell includes:

[0014] S01. Select a matching gasket according to the anvil area of ​​the diamond anvil device and pre-press it so that an indentation appears at the center of the gasket;

[0015] S02. Drill a hole at the center of the indentation of the seal and install the seal to the center of the lower anvil surface of the diamond anvil;

[0016] S03. Add an insulating layer at the punching position, cover the hole and the sealing surface, and complete pre-pressing;

[0017] S04. Drill a hole in the center of the insulating layer for placing a hydrogen source material;

[0018] S05. Place a catalyst on the anvil surface of the diamond anvil.

[0019] Furthermore, in S03, the insulating layer is prepared by uniformly mixing aluminum oxide and black glue.

[0020] Furthermore, in S1, encapsulating the hydrogen source material and the metal raw material into the high pressure chamber includes:

[0021] S101. Placing a hydrogen source material in the center hole of the insulating layer;

[0022] S102. Place the metal raw material on the upper anvil surface.

[0023] Furthermore, the hydrogen source material is ammonia borane and its derivatives, and the metal material is a high-purity metal hafnium target.

[0024] Furthermore, S05 also includes: first placing a primary electrode; then depositing a secondary electrode on the anvil surface of the diamond anvil, and the secondary electrode cooperates with the primary electrode to perform electrical testing.

[0025] Furthermore, in S2, the target pressure is 6 to 400 GPa.

[0026] Compared with the prior art, the present invention can achieve at least one of the following technical effects:

[0027] 1) The HfHn provided by the present invention has a high hydrogen content, which improves the energy density of the metal hydride material. 14 It is the metal hydride with the highest hydrogen content discovered in experiments so far. By increasing the content of hydrogen atoms in metal hydrides, the atomically bonded hydrogen is directly compressed to achieve hydrogen metallization, which may obtain the properties of metallic hydrogen. This makes metal hydride materials (i.e. hydrogen-rich materials) of great research value and a viable candidate material for realizing disruptive energetic materials that tend toward metallic hydrogen.

[0028] 2) In the preparation method of the present invention, by adding a catalyst, hydrogen decomposition is promoted and participates in the reaction, and the pressure required for the metal material and hydrogen to react is reduced. Compared with the reaction of metal and hydrogen without adding a catalyst, the synthesis pressure of HfHn is reduced from the existing 12.4 to 600 GPa to 6 to 400 GPa, which is reduced by 6.4 to 200 GPa. The method of the present invention ensures the repeatability of the experiment, reduces the difficulty of the experiment, and becomes an important means to explore new metal super hydrogen materials.

[0029] Other features and advantages of the present invention will be described in the following description, and part of them may become obvious from the description, or may be understood by practicing the present invention. The purpose and other advantages of the present invention may be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference numerals refer to like components throughout the drawings.

[0031] Figure 1 A physical diagram of the position of the secondary electrode and the metal Hf raw material on the upper anvil surface of the diamond anvil and the position of the hydrogen source material on the lower anvil surface in an embodiment of the present invention;

[0032] Figure 2 is the HfH of the present invention 14 XRD spectrum of

[0033] Figure 3 is the HfH of the present invention 14 High voltage electrical properties test diagram. DETAILED DESCRIPTION

[0034] A metal hydride material and a preparation method thereof are further described in detail below in conjunction with specific examples. These examples are only used for comparison and explanation purposes, and the present invention is not limited to these examples.

[0035] The present invention provides a metal hydride material, the chemical formula of the metal hydride material is HfHn, wherein n is the number of H atoms contained in the HfHn molecule, and the value range of n is 3.75-18, for example, 4-18.

[0036] Specifically, HfHn may include Hf4H 15 , Hf3H 13 、HfH6、HfH9、HfH 10 and HfH 14 And other materials.

[0037] Specifically, in the HfHn of the present invention, HfH 14 It is the metal hydride with the highest molar hydrogen content discovered so far. 14 The study of the crystal structure and electrical transport properties is expected to reveal the structure-activity relationship of metal hydride materials and provide ideas for obtaining the properties of metallic hydrogen.

[0038] The present invention also provides a method for preparing a metal hydride material, which can reduce the pressure required for the preparation process of the metal hydride material by adding a catalyst; the method has universal applicability and is particularly suitable for the high-pressure and high-temperature preparation and in-situ structural and electrical property characterization of metal hydride materials.

[0039] The present invention provides a method for preparing a metal hydride material, comprising the following steps:

[0040] S1. Encapsulating hydrogen source materials and metal raw materials into a high-pressure cavity; a catalyst is placed in the high-pressure cavity;

[0041] S2. Pressurize the hydrogen source material and the metal raw material, and after reaching the target pressure, start heating, and maintain the pressure and temperature to prepare the metal hydride material HfHn.

[0042] It should be noted that the above-mentioned catalyst includes Pt, Pd, Au, Rh, Ru or Re.

[0043] It should be noted that the preparation of the above-mentioned metal hydride material is carried out in a high-pressure device, which is a diamond anvil cell device.

[0044] Specifically, before S1, the step further includes: completing the preparation work of the diamond anvil device, and the preparation work of the diamond anvil device includes:

[0045] S01. Select a matching gasket according to the anvil area of ​​the diamond anvil device and pre-press it so that an indentation appears at the center of the gasket;

[0046] S02. Then, a hole is punched at the center of the indentation of the seal, and the seal is mounted to the center of the lower anvil surface of the diamond anvil;

[0047] S03. Then, an insulating layer is added at the punching position to cover the hole and the sealing surface, and pre-pressing is completed;

[0048] S04. Then, a hole is punched in the center of the insulating layer for placing a hydrogen source material;

[0049] S05. Then, a catalyst is placed on the diamond anvil, and the catalyst can promote hydrogen cracking.

[0050] Specifically, in the above S01, the gasket is made of T301 stainless steel.

[0051] Specifically, in the above S02, the punching can be performed by laser punching or mechanical punching.

[0052] Specifically, in the above S03, in order to ensure the high strength of the insulating layer, the insulating layer is prepared by uniformly mixing aluminum oxide and black glue (STYCAST2850FT thermal conductive epoxy resin) in a mass ratio of 4:1.

[0053] Specifically, in the above S05, the material of the catalyst includes alkali metals, alkaline earth metals, transition metals or lanthanide elements; for example, the catalyst can be Li, Ca, Fe, Pd, Pt or Ce, etc.

[0054] Specifically, the diameter of the holes on the sealing gasket is 300 μm, and the diameter of the holes on the insulating layer is 20-200 μm.

[0055] It should be noted that, in order to perform electrical testing, the above S05 includes: first placing a primary electrode for electrical testing; then depositing a secondary electrode on the anvil surface of the diamond anvil, and the secondary electrode cooperates with the primary electrode to perform electrical testing.

[0056] Specifically, in the above S1, packaging the hydrogen source material and the metal raw material into the high-pressure cavity includes:

[0057] S101. Placing a hydrogen source material in the center hole of the insulating layer;

[0058] S102. Place the metal raw material on the upper anvil surface.

[0059] Specifically, the hydrogen source material is ammonia borane and its derivatives, which release hydrogen to participate in the reaction at a temperature below 350° C. under normal pressure, and can be conveniently used in the preparation reaction of hydrides; the metal material is a high-purity metal hafnium target.

[0060] Specifically, in the above S102, the thickness of the metal raw material is 0.2 to 5 μm.

[0061] Specifically, in the above S2, the pressure loading is to apply pressure to the piston cylinder through the gear reduction pressurizing equipment.

[0062] Specifically, in the above S2, the pressure of the sample in the cavity is calibrated by the first-order Raman peak of diamond.

[0063] Specifically, in the above S2, heating the raw material under high pressure can be performed by laser heating.

[0064] Specifically, in the above S2, the target pressure required for the synthesis of metal hydride materials in the high-pressure chamber is 6 to 400 GPa, and the pressure holding time varies from a few minutes to a few hours. For example, HfH 14 The synthesis pressure of Hf3H is 243GPa, and the holding time is 10 minutes; 13 The synthesis pressure of HfH is 60GPa, and the holding time is 10 minutes; 10 The synthesis pressure is 200 GPa and the holding time is 20 minutes.

[0065] Specifically, in the above S2, the target temperature required for the synthesis of metal hydride materials in the high pressure chamber is room temperature to 3000K, such as HfH 14 The synthesis temperature is 2000K, Hf3H 13 The synthesis temperature is 2000K, HfH 10 The synthesis temperature is 2500K.

[0066] It should be noted that in the above S2, the target pressure has no direct relationship with the value of n in the metal hydride material, but in most cases, the larger the n, the larger the target pressure, such as Hf3H 13 The synthetic pressure of HfH is 60GPa. 10 The synthetic pressure of HfH is 200GPa. 14 The combined pressure is 243 GPa.

[0067] Specifically, in the above S2, the metal hydride material obtained is a block solid with a density of 7.3 g / cm 3 ~8.7g / cm 3 The specific density is determined by the value of n. The larger the n value, the smaller the density. For example, Hf3H 13 The density is 8.5g / cm 3 , HfH 10 The density is 7.9g / cm 3 , HfH 14 The density is 7.5g / cm 3 .

[0068] Compared with the prior art, the HfHn provided by the present invention has a higher hydrogen content, which improves the energy density of the metal hydride material. 14 It is the metal hydride with the highest hydrogen content discovered so far. By increasing the content of hydrogen atoms in metal hydrides, the atomically bonded hydrogen is directly compressed to achieve hydrogen metallization, which may obtain the properties of metallic hydrogen. This makes metal hydride materials of great research value and a viable candidate material for realizing disruptive energetic materials that tend toward metallic hydrogen.

[0069] In the preparation method of the present invention, by adding a catalyst, hydrogen decomposition is promoted and participates in the reaction, and the pressure required for the metal material and hydrogen to react is reduced. Compared with the reaction of metal and hydrogen without adding a catalyst, the synthesis pressure of HfHn is reduced from 12.4 to 600 GPa to 6 to 400 GPa, which is reduced by 6.4 to 200 GPa. The method of the present invention ensures the repeatability of the experiment, reduces the difficulty of the experiment, and becomes an important means to explore new metal hydride materials.

[0070] Example 1

[0071] This embodiment provides a metal hydride material and a preparation method thereof. The metal hydride material in this embodiment is HfH 14 , the preparation method comprises:

[0072] S1. Complete the preparation of the diamond anvil device;

[0073] S2. Complete the packaging of metal raw materials and hydrogen source materials;

[0074] S3. Complete pressure loading to the target pressure and laser heating to the target temperature, then keep the temperature and pressure to obtain HfH 14 .

[0075] Specifically, the preparation of the diamond anvil cell in S1 is carried out through the following steps:

[0076] S01. Select a 50 μm diamond anvil with a rotation speed of 300 rpm to pre-press the seal, so that an indentation appears at the center of the seal;

[0077] S02. Then, a hole with a diameter of 300 μm is punched at the center of the indentation of the seal, and the seal is mounted to the center of the lower anvil surface of the diamond;

[0078] S03. Then, the insulating layer covers the hole and the upper surface of the gasket, and completes the pre-pressing;

[0079] S04. Then, a hole with a diameter of 50 μm is punched in the center of the insulating layer for placing a hydrogen source material;

[0080] S05. Then, place the electrodes once for electrical testing;

[0081] S06. Then, a secondary electrode Pt is deposited on the anvil surface of the diamond anvil, and Pt also acts as a catalyst to promote hydrogen decomposition.

[0082] Specifically, the gasket is made of T301 stainless steel.

[0083] Specifically, the punching is performed by laser punching.

[0084] Specifically, the insulating layer material is prepared by uniformly mixing aluminum oxide and black glue in a ratio of 4:1.

[0085] Specifically, the catalyst is Pt metal, which is deposited on the anvil surface of the high-pressure anvil by magnetron sputtering in the form of a thin film with a thickness of 0.4 μm.

[0086] Specifically, in S2, the packaging of the metal raw material and the hydrogen source material is achieved by the following steps:

[0087] S101. Placing a hydrogen source material in the center hole of the insulating layer;

[0088] S102. Place the high-purity metal raw material on the upper anvil surface.

[0089] Specifically, the hydrogen source material is ammonia borane and its derivatives, and the metal material is high-purity metal hafnium, and the thickness thereof is 1 μm.

[0090] Specifically, in the above S3, the target pressure is 243 GPa; the target temperature is 2000 K, and the heat and pressure holding time is 10 minutes.

[0091] Specifically, in the above S3, the pressure loading is to apply pressure to the piston cylinder through the gear reduction pressurizing equipment.

[0092] Specifically, the positions of the secondary electrode, the metal film and the hydrogen source material in the diamond anvil cell are as follows: Figure 1 shown.

[0093] The HfH synthesized under high pressure in this example 14 The X-ray diffraction pattern of the sample is as follows Figure 2 As shown, its X-ray spectrum is consistent with the theoretical calculation of HfH 14 The results are consistent, proving that HfH is generated by high pressure 14 .

[0094] The HfH synthesized under high pressure in this example 14 The electrical test of the samples is as follows: Figure 3 As shown, the resistance appears zero near 83K, proving that HfH 14 It is a superconductor and belongs to the metallic hydrogen class of materials.

[0095] The HfH synthesized under high pressure in this example 14 The density of the sample is 7.5 g / cm 3 .

[0096] Comparative Example 1

[0097] This comparative example provides a HfH 14 High pressure and high temperature preparation method. The steps of this comparative example are roughly the same as those of Example 1, except that:

[0098] In S1, no catalyst was added.

[0099] In S3, HfH is formed 14 The required pressure loading is 300 GPa.

[0100] Comparing Example 1 with Comparative Example 1, due to the effect of the catalyst, HfH 14 The synthesis pressure is 243 GPa, which is 57 GPa lower than 300 GPa of Comparative Example 1.

[0101] Example 2

[0102] This embodiment provides a metal hydride material and a preparation method thereof. The metal hydride material in this embodiment is Hf3H 13 The steps are roughly the same as those in Example 1, except that:

[0103] In S04, a hole with a diameter of 100 μm was made in the center of the insulating layer;

[0104] Specifically, the catalyst is Pd metal, and the thickness of the catalyst film is 0.4 μm.

[0105] Specifically, in S102, in a vacuum environment, high-purity metal hafnium is deposited on the upper anvil surface by a DC pulse magnetron sputtering method, and the deposition area covers the catalyst film. The thickness of the high-purity metal hafnium is 2 μm.

[0106] In S3, the target pressure is 60 GPa; the target temperature is 2000 K, and the temperature and pressure holding time is 10 minutes.

[0107] The Hf3H synthesized under high pressure in this example 13 Electrical test experiments found that the resistance appeared to be zero near 44K, proving that the generated material is a superconductor and belongs to the metallic hydrogen class of materials. Theoretical prediction of Hf3H 13 The superconducting transition temperature is 46K, which is close to the experimental test value of 44K, proving that the material is Hf3H 13 .

[0108] The Hf3H synthesized under high pressure in this example 13 The density is 8.5g / cm3 .

[0109] Comparative Example 2

[0110] This comparative example provides a Hf3H 13 High pressure and high temperature preparation method. The steps of this comparative example are roughly the same as those of Example 2, except that:

[0111] In S1, no catalyst was added.

[0112] In S3, Hf3H is formed 13 The required pressure loading is 100 GPa.

[0113] In Comparative Example 2, Hf3H 13 The synthesis pressure is 100 GPa. Due to the effect of the catalyst, Hf3H 13 The synthesis pressure is 60GPa, which is reduced by 40GPa.

[0114] Example 3

[0115] This embodiment provides a metal hydride material and a preparation method thereof. The metal hydride material in this embodiment is HfH 10 The steps are roughly the same as those in Example 1, except that:

[0116] In S04, a hole with a diameter of 100 μm was made in the center of the insulating layer;

[0117] Specifically, the catalyst is Pd metal, and the thickness of the catalyst film is 0.2 μm.

[0118] Specifically, in S102, in a vacuum environment, high-purity metal hafnium is deposited on the upper anvil surface by a DC pulse magnetron sputtering method, and the deposition area covers the catalyst film. The thickness of the high-purity metal hafnium is 2 μm.

[0119] In S3, the target pressure is 200 GPa; the target temperature is 2500 K, and the temperature and pressure holding time is 10 minutes.

[0120] The HfH synthesized under high pressure in this example 10 Electrical test experiments found that the resistance appeared to be zero near 230K, proving that the generated material is a superconductor and belongs to the metallic hydrogen class of materials. Theoretical prediction of HfH 10 The superconducting transition temperature is 234K, which is close to the experimental test value, proving that the material is HfH 10 .

[0121] The HfH synthesized under high pressure in this example 10 The density is 7.9g / cm 3 .

[0122] Comparative Example 3

[0123] This comparative example provides a HfH 10 High pressure and high temperature preparation method. The steps of this comparative example are roughly the same as those of Example 3, except that:

[0124] In S1, no catalyst was added.

[0125] In S3, the pressure loading required to form HfH10 is 300 GPa.

[0126] In Comparative Example 3, HfH 10 The synthesis pressure is 300 GPa. Due to the effect of the catalyst, HfH 10 The synthesis pressure is 200 GPa, which is reduced by 100 GPa.

[0127] Example 4

[0128] This embodiment provides a metal hydride material and a preparation method thereof. The metal hydride material in this embodiment is Hf4H 15 The steps are roughly the same as those in Example 1, except that:

[0129] In S04, a hole with a diameter of 200 μm was made in the center of the insulating layer;

[0130] Specifically, the catalyst is Pd metal, and the thickness of the catalyst film is 0.2 μm.

[0131] Specifically, in S102, in a vacuum environment, high-purity metal hafnium is deposited on the upper anvil surface by a DC pulse magnetron sputtering method, and the deposition area covers the catalyst film. The thickness of the high-purity metal hafnium is 2 μm.

[0132] In S3, the target pressure is 6 GPa; the target temperature is 1500 K, and the temperature and pressure holding time is 20 minutes.

[0133] The Hf4H synthesized under high pressure in this example 15 The electrical test experiment found that the resistance appeared zero near 4K, proving that the generated Hf4H 15 The material is a superconductor and belongs to the metallic hydrogen class of materials. 15 The superconducting transition temperature is 4.5K, proving that the material is Hf4H 15 .

[0134] The Hf4H synthesized under high pressure in this example 15 The density is 8.7g / cm 3 .

[0135] Comparative Example 4

[0136] This comparative example provides a Hf4H 15High pressure and high temperature preparation method. The steps of this comparative example are roughly the same as those of Example 4, except that:

[0137] In S1, no catalyst was added.

[0138] In S3, Hf4H is formed 15 The required pressure loading is 12.4 GPa.

[0139] In Comparative Example 4, Hf4H 15 The synthesis pressure is 12.4 GPa. Due to the effect of the catalyst, Hf4H 15 The synthesis pressure is 6 GPa, which is reduced by 6.4 GPa.

[0140] It can be seen from the embodiments and comparative examples of the present invention that the present invention can prepare HfHn, wherein the range of n is 3.75-18, which increases the hydrogen content and energy density of the metal hydride material; and by adding a catalyst, the pressure required for the synthesis of HfHn is effectively reduced. It is reduced from 12.4 to 600 GPa to 6 to 400 GPa, which is a reduction of 6.4 to 200 GPa. The method of the present invention ensures the repeatability of the experiment, reduces the difficulty of the experiment, and becomes an important means to explore new metal hydride materials.

[0141] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A metal hydride material, characterized in that: The chemical formula of the metal hydride material is HfHn, and the value range of n is 3.75~14; The metal hydride material is prepared by the following preparation method: S1. Encapsulating hydrogen source materials and metal raw materials into a high-pressure cavity; a catalyst is placed in the high-pressure cavity; the hydrogen source material is ammonia borane and its derivatives, and the metal raw material is a high-purity metal hafnium target; S2. Pressurize the hydrogen source material and the metal raw material. After reaching the target pressure, start laser heating and maintain the pressure and temperature to prepare the metal hydride material HfHn.

2. A method for preparing a metal hydride material, characterized in that: The steps include: S1. Encapsulating hydrogen source materials and metal raw materials into a high-pressure cavity; a catalyst is placed in the high-pressure cavity; the hydrogen source material is ammonia borane and its derivatives, and the metal raw material is a high-purity metal hafnium target; S2. Pressurize the hydrogen source material and the metal raw material. After reaching the target pressure, start laser heating and maintain the pressure and temperature to prepare the metal hydride material HfHn, where the value of n ranges from 3.75 to 14.

3. The preparation method according to claim 2, characterized in that: The catalyst includes an alkali metal, an alkaline earth metal, a transition metal or a lanthanide element.

4. The preparation method according to claim 3, characterized in that: The catalyst includes Li, Ca, Fe, Pd, Pt or Ce.

5. The preparation method according to claim 2, characterized in that: Before S1, the process also includes: completing the preparation work of the diamond anvil device, and the preparation work of the diamond anvil device includes: S01. Select a matching seal according to the anvil area of ​​the diamond anvil device and pre-press it so that an indentation appears at the center of the seal; S02. Drill a hole at the center of the indentation of the seal and install the seal to the center of the lower anvil surface of the diamond anvil; S03. Add an insulating layer at the punching position, cover the hole and the gasket surface, and complete pre-pressing; S04. Drill a hole in the center of the insulating layer for placing a hydrogen source material; S05. Place a catalyst on the anvil surface of the diamond anvil.

6. The preparation method according to claim 5, characterized in that: In the S03, the insulating layer is prepared by uniformly mixing aluminum oxide and black glue.

7. The preparation method according to claim 2, characterized in that: In S1, packaging the hydrogen source material and the metal raw material into the high-pressure cavity includes: S101. Placing a hydrogen source material in the center hole of the insulating layer; S102. Place the metal material on the upper anvil surface.

8. The preparation method according to claim 5, characterized in that: The S05 also includes: first placing a primary electrode; then depositing a secondary electrode on the anvil surface of the diamond anvil, and the secondary electrode cooperates with the primary electrode to perform electrical testing.

9. The preparation method according to claim 2, characterized in that: In S2, the target pressure is 6~400GPa.

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