High-pressure diamond inclusion and preparation method therefor

Abstract

The present application relates to the technical field of novel materials, and provides a high-pressure diamond inclusion and a preparation method therefor. The high-pressure diamond inclusion comprises a high-pressure diamond capsule and a solid high-pressure material located in the high-pressure diamond capsule, wherein the high-pressure material is a material at a pressure greater than 1 atmosphere. The preparation method comprises: using a target material and two or more layers of thin-film carbon materials as primary raw materials, and performing high-temperature and high-pressure treatment on the primary raw materials to obtain the high-pressure diamond inclusion, wherein the target material is distributed between two adjacent layers of thin-film carbon materials, and the high-temperature and high-pressure treatment converts the carbon materials into the high-pressure diamond capsule covering the high-pressure target material. In the present application, thin-film carbon materials are used as raw materials, so that an internal pressure state of a synthesized diamond inclusion, and the granularity, volume fraction and spatial distribution state of a covered material can be adjusted according to requirements, thereby achieving high-controllable batch preparation of a synthesized high-pressure diamond inclusion composite material.

Description

Diamond high-pressure inclusion and preparation method thereof

[0001] The present application claims priority to the Chinese patent application No.CN202410821681.1, filed on June 24, 2024, entitled "Diamond high-pressure inclusion and preparation method thereof", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of new materials, and relates to a diamond high-pressure inclusion and a preparation method thereof. BACKGROUND

[0003] Natural diamond high-pressure inclusions are derived from geological minerals, and are formed because natural diamond captures inclusion materials under high pressure during the formation process in the mantle environment and carries them to the earth's surface to be discovered. The extremely high strength of diamond enables the inclusion to maintain the high pressure of the underground environment to a certain extent when it is brought to the surface environment, so that the material structure and properties of the high-pressure state can be preserved in the form of the inclusion in the normal pressure environment, thus having great research value and application value. However, the material types and forms of natural diamond inclusions cannot be artificially controlled, and are very rare and difficult to obtain.

[0004] The Chinese patent No.220210515692.8 discloses a method for preparing high-pressure state materials that can be separated from a high-pressure device. In this technology, carbon materials are mechanically mixed with target materials, and then are converted into diamond high-pressure inclusions under high temperature and high pressure. Although this method is simple, the carbon materials and target materials are not easy to mix uniformly, which leads to the difficulty in controlling the spatial distribution and particle size of the high-pressure state materials in the obtained inclusions, and the limited success rate of complete encapsulation of the target materials.

[0005] In view of this, the present application is proposed. SUMMARY

[0006] The present application provides a diamond high-pressure inclusion and a preparation method thereof, to solve the defects in the prior art that the spatial distribution and particle size of the high-pressure state materials in the diamond high-pressure inclusion are difficult to control, and the success rate of complete encapsulation of the target materials is limited.

[0007] In a first aspect, the present application provides a method for preparing a diamond high-pressure inclusion, the diamond high-pressure inclusion comprising a diamond high-pressure cell and a solid high-pressure state material located in the diamond high-pressure cell; the high-pressure state material comprising a material under a pressure greater than 1 atmosphere; the method comprising: obtaining by high-temperature and high-pressure treatment with a solid target material and two or more layers of thin film carbon material as main raw materials; and wrapping the target material with a certain spatial distribution and / or size between adjacent two layers of the thin film carbon material.

[0008] The high-temperature and high-pressure treatment converts the carbon material into the diamond high-pressure cell wrapping the high-pressure state material.

[0009] The present application first wraps the target material with a certain spatial distribution and / or size between adjacent two layers of the thin film carbon material, which can be collectively referred to as a composite thin film. The composite thin film is used as the main raw material for high-temperature and high-pressure treatment, thereby taking advantage of the technical advantages of thin film preparation process and the technical characteristics of high-temperature and high-pressure treatment of converting carbon into diamond to control the spatial distribution and / or particle size of the high-pressure state material in the diamond high-pressure inclusion.

[0010] The carbon material suitable for the present application includes but is not limited to one or a combination of two or more of graphite, carbon black, graphene, fullerene, carbon nanotube, glassy carbon, and amorphous carbon.

[0011] The target material suitable for the present application includes but is not limited to metal, ceramic, and semiconductor material.

[0012] According to the method for preparing the diamond high-pressure inclusion as described above provided by the present application, before the high-temperature and high-pressure treatment, the thin film carbon material completely wraps the target material, and there is no gap between the adjacent two layers of the wrapped thin film carbon material.

[0013] According to the method for preparing the diamond high-pressure inclusion as described above provided by the present application, the preparation of the raw material comprises: first arranging the target material on the thin film carbon material, and then arranging the thin film carbon material.

[0014] The thin film carbon material is formed by a thin film preparation process, and the thin film preparation process comprises one or two or more of physical vapor deposition, chemical vapor deposition, atomic layer deposition, and wet chemical method.

[0015] According to the method for preparing the diamond high-pressure inclusion as described above provided by the present application, the total thickness of the composite thin film composed of the adjacent two layers of the thin film carbon material and the target material therebetween is D, and the value range of D is 10 nm to 50 μm.

[0016] The thickness of the thin film-shaped carbon material is d, and d is greater than or equal to 30% of D.

[0017] According to the diamond high-pressure inclusion provided in the present application, the form of the target material includes one of a particle, a rod, and a sheet, or a combination of two or more thereof.

[0018] Preferably, the target material includes nanoparticles in a monodisperse state.

[0019] According to the preparation method of the diamond high-pressure inclusion provided in the present application, the high-temperature and high-pressure treatment includes: treating the raw material under the condition of 15-100 GPa and 1200-2500 ℃.

[0020] According to the preparation method of the diamond high-pressure inclusion provided in the present application, the raw material is treated under the condition of 15-100 GPa and 1200-2500 ℃ for 1-20 minutes.

[0021] In the high-temperature and high-pressure process of the present application, methods including but not limited to resistance heating, laser heating, and other methods that can generate high temperature can be used.

[0022] The present application uses a thin film-shaped carbon material as one of the raw materials, and can realize the regulation of the structure (phase) and pressure value of the diamond high-pressure inclusion by changing the pressure and temperature parameters in the high-temperature and high-pressure process.

[0023] According to the preparation method of the diamond high-pressure inclusion provided in the present application, the high-temperature and high-pressure treatment is performed by using a diamond anvil cell or a large cavity press.

[0024] According to the preparation method of the diamond high-pressure inclusion provided in the present application, the preparation method comprises:

[0025] The first layer of thin film-shaped carbon material is formed by using a thin film preparation process;

[0026] The target material is formed on the first layer of thin film-shaped carbon material to obtain a composite layer;

[0027] The second layer of thin film-shaped carbon material is formed on the composite layer by using a thin film preparation process to obtain a composite thin film;

[0028] One or more composite thin films are stacked and then subjected to high-temperature and high-pressure treatment and pressure relief to obtain the diamond high-pressure inclusion. For example, one composite thin film is subjected to high-temperature and high-pressure treatment, and the process is shown in FIG. 1.

[0029] In a second aspect, the present application also provides a diamond high-pressure inclusion, which is prepared by the preparation method of the diamond high-pressure inclusion as described above.

[0030] Preferably, the high-pressure state material comprises nanoparticles in a monodisperse state.

[0031] The adjacent two layers of the thin film-shaped carbon material are of the same material or different materials.

[0032] The present application provides a diamond high-pressure inclusion and a preparation method thereof. The diamond high-pressure inclusion comprises a diamond high-pressure chamber and a solid high-pressure state material in the diamond high-pressure chamber. The high-pressure state material comprises a material in a state of a pressure greater than 1 atmosphere. The preparation method comprises the following steps: using a target material and a carbon material in a thin film shape as main raw materials to perform high-temperature and high-pressure treatment to obtain the diamond high-pressure inclusion. The target material is distributed between adjacent two layers of the thin film-shaped carbon material. The high-temperature and high-pressure treatment converts the carbon material into the diamond high-pressure chamber which encapsulates the high-pressure state target material. The present application can adjust the internal pressure state, the particle size, the volume fraction, the spatial distribution state, etc. of the synthesized diamond inclusion according to requirements by using the carbon material in a thin film shape as the raw material, and further realizes batch preparation of the diamond high-pressure inclusion composite material with high controllability.

[0033] The method of the present application can obtain products in a multi-scale range from nanometers to centimeters to meet different application purposes. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0035] FIG. 1 is a schematic diagram of the main process for preparing a diamond high-pressure inclusion.

[0036] FIG. 2 is a cross-sectional transmission electron microscope (TEM) photo of a carbon-gold-carbon composite film according to Embodiment 2 of the present application.

[0037] FIG. 3 is a planar TEM photo of a carbon-gold-carbon composite film according to Embodiment 2 of the present application.

[0038] FIG. 4 is an electron energy loss spectrum of a carbon layer according to Embodiment 2 of the present application.

[0039] FIG. 5 is a high-resolution TEM photo of a diamond high-pressure inclusion according to Embodiment 2 of the present application, in which a diamond encapsulates gold nanoparticles in a high-pressure state.

[0040] FIG. 6 is a high-resolution TEM photo of a diamond high-pressure inclusion according to Embodiment 3 of the present application, in which a diamond encapsulates gold nanoparticles in a high-pressure state. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] The diamond high-pressure inclusions of this application and their preparation method are described below with reference to Figures 1 to 6.

[0043] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0044] The following examples illustrate the preferred embodiments proposed in this application.

[0045] Example 1

[0046] A method for preparing diamond high-pressure inclusions, comprising the following steps:

[0047] (1) Select carbon target material and adopt magnetron sputtering method. The magnetron sputtering process parameters are: RF sputtering power 200W, time 2600s, Ar gas pressure 20mTorr, Ar gas flow rate 30sccm. Sputter a carbon layer with a thickness of 20nm on the polyvinyl alcohol hydrogel layer substrate, which is called the first carbon layer.

[0048] (2) Select a gold target and use magnetron sputtering to sputter gold nanoparticles onto the carbon layer obtained in step (1). The magnetron sputtering process parameters are: RF sputtering power 200W, time 6s, Ar gas pressure 20mTorr, Ar gas flow rate 30sccm, to obtain a composite layer with gold nanoparticles uniformly distributed on the surface.

[0049] (3) Select a carbon target and use magnetron sputtering to sputter a carbon layer onto the composite layer obtained in step (2). The magnetron sputtering process parameters are: RF sputtering power 200W, time 2600s, Ar gas pressure 20mTorr, Ar gas flow rate 30sccm. This carbon layer is referred to as the second carbon layer, and a composite film is obtained. Partial areas of the first and second carbon layers in the composite film form sp... 2 Bonding, the sp 2 The bonding ensures that the gold nanoparticles between the first carbon layer and the second carbon layer are uniformly distributed. That is, before the high temperature and high pressure treatment, the first carbon layer and the second carbon layer in the composite film completely encapsulate the gold nanoparticles, and there are no gaps between the first carbon layer and the second carbon layer in the composite film.

[0050] (4) The composite film obtained in step (3) is dissolved in deionized water to remove the polyvinyl alcohol hydrogel layer, thereby obtaining a film composed of a first carbon layer, gold nanoparticles and a second carbon layer and having a sandwich structure, and the total thickness of the film is 60 nm.

[0051] (5) The 10 layers of the film obtained in step (4) are stacked, naturally air-dried and then cut into square blocks with a side length of 90 μm; then the blocks are loaded into a diamond anvil press, a layer of sodium chloride is laid on the upper and lower pressure cavities as a heat insulation layer, the pressure is increased to 30 GPa, laser heating is performed to 1700 °C and maintained for 2 minutes, and finally the pressure is released to normal pressure and the diamond inclusion is taken out.

[0052] The diamond inclusion obtained in step (5) is subjected to transmission electron microscope analysis, and the results show that the gold nanoparticles are uniformly distributed in the nanocrystalline diamond, and the (111) crystal face spacing of the gold nanoparticles encapsulated by the diamond is reduced relative to the initial state, indicating that the gold nanoparticles are in a high-pressure state.

[0053] Example 2

[0054] A method for preparing a diamond high-pressure inclusion, comprising the following steps:

[0055] (1) A carbon target is selected, and a carbon layer with a thickness of 30 nm is sputtered on a polyvinyl alcohol hydrogel layer substrate by a magnetron sputtering method, and the magnetron sputtering process parameters are as follows: a radio frequency sputtering power of 200 W, a time of 3900 s, an Ar gas pressure of 20 mTorr and an Ar gas flow rate of 30 sccm, and the carbon layer is recorded as a first carbon layer.

[0056] (2) A gold target is selected, and gold nanoparticles are sputtered on the carbon layer obtained in step (1) by a magnetron sputtering method, and the magnetron sputtering process parameters are as follows: a radio frequency sputtering power of 200 W, a time of 9 s, an Ar gas pressure of 20 mTorr and an Ar gas flow rate of 30 sccm, thereby obtaining a composite layer with uniformly distributed gold nanoparticles on the surface.

[0057] (3) A carbon target is selected, and a carbon layer is sputtered on the composite layer obtained in step (2) by a magnetron sputtering method, and the magnetron sputtering process parameters are as follows: a radio frequency sputtering power of 200 W, a time of 3900 s, an Ar gas pressure of 20 mTorr and an Ar gas flow rate of 30 sccm, and the carbon layer is recorded as a second carbon layer, thereby obtaining a composite film, and the cross-sectional transmission electron microscope photograph and the planar transmission electron microscope photograph of the film are shown in FIGS. 2 and 3, and the electron energy loss spectrum of the carbon layer in the film is shown in FIG. 4, and it can be seen that the first carbon layer and the second carbon layer in the composite film form sp 2 bonding in some regions. 2The bonding keeps the gold nanoparticles between the first carbon layer and the second carbon layer in a uniformly distributed state, that is, before the high-temperature and high-pressure treatment, the first carbon layer and the second carbon layer in the composite film completely wrap the gold nanoparticles, and there is no gap between the first carbon layer and the second carbon layer in the composite film.

[0058] (4) The composite film obtained in step (3) is dissolved in deionized water to remove the polyvinyl alcohol hydrogel layer, and a film composed of a first carbon layer, gold nanoparticles and a second carbon layer in a sandwich structure is obtained, and the total thickness of the film is 90 nm.

[0059] (5) The 20 layers of the film obtained in step (4) are stacked, naturally air-dried, and then cut into square blocks with a side length of 90 μm; then loaded into a diamond anvil press, the upper and lower pressure cavities are filled with argon gas as a heat insulation layer, pressurized to 30 GPa, heated to 1700 ℃ and kept for 2 minutes; finally, the pressure is unloaded to normal pressure, and the diamond inclusion is taken out.

[0060] The diamond inclusion obtained in step (5) is subjected to transmission electron microscope analysis, as shown in FIG. 5, the gold nanoparticles are uniformly distributed in the nanocrystalline diamond, compared with FIGS. 2 and 3, the distribution and size of the gold nanoparticles wrapped by the diamond are preserved, and the average (111) crystal plane spacing of the gold nanoparticles is , which indicates that it is in a high-pressure state.

[0061] Example 3

[0062] A method for preparing a diamond high-pressure inclusion, the steps of which are as follows:

[0063] (1) Select a carbon target, use a magnetron sputtering method, and the magnetron sputtering process parameters are: radio frequency sputtering power 200 W, time 3900 s, Ar gas pressure 20 mTorr, Ar gas flow rate 30 sccm, sputter a carbon layer with a thickness of 30 nm on a polyvinyl alcohol hydrogel layer substrate, which is recorded as a first carbon layer.

[0064] (2) Select a gold target, use a magnetron sputtering method, and sputter gold nanoparticles on the carbon layer obtained in step (1), the magnetron sputtering process parameters are: radio frequency sputtering power 200 W, time 9 s, Ar gas pressure 20 mTorr, Ar gas flow rate 30 sccm, to obtain a composite layer with uniformly distributed gold nanoparticles on the surface.

[0065] (3) Select a carbon target, use a magnetron sputtering method, and sputter a carbon layer on the composite layer obtained in step (2), the magnetron sputtering process parameters are: radio frequency sputtering power 200 W, time 3900 s, Ar gas pressure 20 mTorr, Ar gas flow rate 30 sccm, the carbon layer is recorded as a second carbon layer, and a composite film is obtained. Part of the region of the first carbon layer and the second carbon layer in the composite film forms sp 2 bonding.2 The bonding keeps the gold nanoparticles between the first carbon layer and the second carbon layer in a uniform distribution state, i.e. before the high-temperature and high-pressure treatment, the first carbon layer and the second carbon layer in the composite film completely wrap the gold nanoparticles, and there is no gap between the first carbon layer and the second carbon layer in the composite film.

[0066] (4) The composite film obtained in step (3) is dissolved in deionized water to remove the polyvinyl alcohol hydrogel layer, thereby obtaining a film composed of a first carbon layer, gold nanoparticles and a second carbon layer, and having a sandwich structure, and the total thickness of the film is 90 nm.

[0067] (5) The 20 layers of the film obtained in step (4) are stacked, naturally air-dried, and then cut into square blocks with a side length of 60 μm; then loaded into a diamond anvil press, the upper and lower pressure cavities are filled with argon gas as a heat insulation layer, pressurized to 40 GPa, heated to 1900 ℃ and kept for 2 minutes; finally, the pressure is unloaded to normal pressure, and the diamond inclusions are taken out.

[0068] The diamond inclusions obtained in step (5) are subjected to transmission electron microscopy analysis, as shown in FIG. 6, the gold nanoparticles are uniformly distributed in the nanocrystalline diamond, and the average (111) interplanar spacing of the gold nanoparticles wrapped by the diamond is which indicates that it is in a high-pressure state, and the pressure is higher than that of the gold nanoparticles in Example 2. It is shown that in the high-temperature and high-pressure process, by changing the pressure and temperature parameters, the structure (phase) and pressure value of the diamond high-pressure inclusion can be controlled.

[0069] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a diamond high-pressure inclusion, wherein the diamond high-pressure inclusion comprises a diamond high-pressure chamber and a solid high-pressure material located within the diamond high-pressure chamber; the high-pressure material is a material under a pressure greater than 1 atmosphere; characterized in that, The preparation method includes: using solid target material and carbon material in the form of two or more thin films as the main raw materials, and processing them under high temperature and high pressure; the target material with a certain spatial distribution and / or a certain size is wrapped between two adjacent layers of the carbon material in the form of thin films; The high-temperature and high-pressure treatment transforms the carbon material into a diamond high-pressure chamber that encapsulates the high-pressure material.

2. The method for preparing diamond high-pressure inclusions according to claim 1, characterized in that, Before high temperature and high pressure treatment, the carbon material in thin film form completely encapsulates the target material, forming a gap between the two adjacent layers of carbon material in thin film form.

3. The method for preparing diamond high-pressure inclusions according to claim 1 or 2, characterized in that, The preparation of the raw material includes: first setting the target material on a carbon material in the form of a thin film, and then setting the carbon material in the form of a thin film; the carbon material in the form of a thin film is formed by a thin film preparation process, which includes one or more of physical vapor deposition, chemical vapor deposition, atomic layer deposition, and wet chemical methods.

4. The method for preparing diamond high-pressure inclusions according to claim 1 or 2, characterized in that, Let D be the total thickness of the composite film composed of two adjacent layers of carbon material in the form of thin films and the target material between them. The value of D ranges from 10 nm to 50 μm. Let d be the thickness of the carbon material in the form of the thin film, where d is greater than or equal to 30%D.

5. The diamond high-pressure inclusion body according to claim 1 or 2, characterized in that, The target material may be in the form of one or more of particles, rods, or flakes. Preferably, the target material comprises monodisperse nanoparticles.

6. The method for preparing diamond high-pressure inclusions according to claim 1 or 2, characterized in that, The high-temperature and high-pressure treatment includes treating the raw material under conditions of 15–100 GPa and 1200–2500 °C.

7. The method for preparing diamond high-pressure inclusions according to claim 6, characterized in that, The raw material is treated at 15–100 GPa and 1200–2500 °C for 1–20 minutes.

8. The method for preparing diamond high-pressure inclusions according to claim 1 or 2, characterized in that, The high-temperature and high-pressure treatment is carried out using a diamond anvil cell or a large-cavity press.

9. The method for preparing diamond high-pressure inclusions according to claim 1 or 2, characterized in that, include: Carbon material with a first thin film morphology formed using thin film fabrication technology; A composite layer is obtained by forming the target material on the carbon material in the form of the first thin film. A second layer of carbon material in the form of a thin film is formed on the composite layer using a thin film preparation process to obtain a composite thin film; After stacking one or more composite films, the diamond high-pressure inclusions are obtained by high-temperature and high-pressure treatment and depressurization.

10. A diamond high-pressure inclusion, characterized in that, It is prepared by the method for preparing diamond high-pressure inclusions according to any one of claims 1 to 8.

11. The diamond high-pressure inclusion body according to claim 10, characterized in that, The high-pressure material comprises monodisperse nanoparticles.

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