Synthetic method of AuGa2 compound, AuGa2 compound and application

Abstract

The invention discloses a synthesis method of an AuGa2 compound, the AuGa2 compound and application, and relates to the technical field of preparation of gold-containing compounds. According to the method, a gold source and liquid gallium are used as raw materials, the liquid gallium is used as a pressure medium for pressurization before reaction, and the reaction process is carried out under pressurized and closed conditions. According to the new path for synthesizing the AuGa2 compound, high-temperature or electric arc melting is not needed, the argon atmosphere requirement is avoided, meanwhile, the power consumption in the synthesis process is very low, the reaction time is very short, and carbon dioxide emission and related potential safety hazards can be reduced. Therefore, the synthesis method provided by the invention can greatly reduce the process cost, and is more energy-saving and environment-friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of gold-containing compounds, and in particular, to a method for synthesizing an AuGa 2 compound and the application of the AuGa 2 compound. Background Art

[0002] AuX 2 (X = In, Ga, Al) compounds have various applications in the fields of jewelry (colored gold), electronic interfaces, and brazing materials. Specifically, AuGa 2 has been widely used as "blue gold" in the jewelry industry; AuGa 2 is used as a solder joint in the electronic field to connect gallium arsenide (GaAs) and gold (Au) contacts and as a lead-free brazing material.

[0003] The existing methods for synthesizing AuGa 2 compounds are mainly carried out by arc melting or in a high-temperature furnace in an argon atmosphere, aiming to melt relevant elements at high temperatures. This process requires maintaining an ultra-high temperature (>1000 °C) for a long time (several hours) and relying on an argon atmosphere (to prevent oxidation), resulting in extremely low technical cost-effectiveness and not meeting environmental protection requirements. Therefore, the existing processes for preparing AuGa 2 generally have the following problems: high cost, resulting in extremely high prices, and the synthesis process is not environmentally friendly.

[0004] Therefore, there is an urgent need to provide a method for synthesizing AuGa 2 compounds that is low-cost and environmentally friendly.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for synthesizing an AuGa 2 compound and the application of the AuGa 2 compound, aiming to provide a new path for synthesizing AuGa 2 to significantly reduce the process cost and make the synthesis process more environmentally friendly.

[0007] The present invention is implemented as follows:

[0008] In a first aspect, the present invention provides a method for synthesizing an AuGa 2 compound, including: using a gold source and liquid gallium as raw materials, and using liquid gallium as a pressure medium to carry out a reaction under pressurized and sealed conditions.

[0009] In an alternative embodiment, the reaction temperature is 15 °C - 30 °C.

[0010] In an alternative embodiment, the reaction pressure is 0.1 GPa - 0.3 GPa.

[0011] In an alternative embodiment, the reaction time is 1 min - 10 min.

[0012] In an alternative embodiment, the gold source is powdered gold;

[0013] and / or, the amount of liquid gallium used is greater than the theoretical amount.

[0014] In an alternative embodiment, it includes: placing the gold source and liquid gallium in the gasket hole of a diamond anvil, filling the gasket hole with liquid gallium, and reacting under pressurized conditions.

[0015] In an alternative embodiment, the gasket is made of rhenium.

[0016] In an alternative embodiment, the hole of the gasket is sealed by two oppositely arranged diamonds, and the two diamonds at both ends are brought closer to each other by adjusting the pressure screw to raise the pressure to the reaction pressure.

[0017] In a second aspect, the present invention provides an AuGa 2 compound, which is prepared by the synthesis method of any one of the foregoing embodiments.

[0018] In a third aspect, the present invention provides the application of the AuGa 2 compound of the foregoing embodiment in the preparation of jewelry or brazing materials.

[0019] The present invention has the following beneficial effects: The present invention uses a gold source and liquid gallium as raw materials, pressurizes with liquid gallium as the pressure medium before the reaction, and the reaction process is carried out under pressurized and sealed conditions. The present invention provides a new path for synthesizing the AuGa 2 compound, which does not require high temperature or arc melting, and the power consumption during the synthesis process is very low; it can eliminate the need for an argon environment, and the required reaction time is very short, and it can also reduce carbon dioxide emissions and related safety hazards. Therefore, the synthesis method provided by the present invention can greatly reduce the process cost and is more energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 For the existing synthesis of AuX 2Physical diagram of the device for the compound; (a) shows the arc melting device; (b) shows the high-temperature synthesis equipment;

[0022] Figure 2 Are the physical photos of the typical diamond anvil device and the sample; (a) shows the diamond anvil device and its working principle diagram; (b) shows the physical photo of the sample;

[0023] Figure 3 Is the physical photo of the diamond anvil cell (DAC) used;

[0024] Figure 4 Are the X-ray diffraction patterns of the existing research based on traditional synthesis techniques and the AuGa 2 diffraction pattern comparison diagram produced by the present invention;

[0025] Figure 5 Is for AuGa 2 The variation law of the unit cell volume of AuGa with pressure and the comparison research diagram of AuGa 2 synthesized by traditional techniques; Detailed implementation manners

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0027] Figure 1 Shows the physical photos of the relevant traditional synthesis equipment. The relevant metal elements (such as gold and gallium) are respectively placed in a copper crucible or in a quartz tube integrated in a high-temperature furnace (>1000 °C). Both devices need to evacuate the sample chamber first, and then continuously introduce argon. The synthesis process takes several hours to ensure sufficient reaction of the elements.

[0028] The existing synthesis of AuGa 2 compound relies on high-temperature conditions and an inert atmosphere, and the preparation process is time-consuming. To address the above problems, the present invention provides a new process for synthesizing AuGa 2 compound, which can synthesize AuGa 2 compound at room temperature and extremely low pressure conditions, and the process cost is significantly reduced.

[0029] An embodiment of the present invention provides a method for synthesizing an AuGa 2 compound, including: using a gold source (such as powdered gold) and liquid gallium as raw materials, and using liquid gallium as the pressure medium to carry out the reaction under pressurized and sealed conditions. The powdered gold and liquid gallium combine under high pressure to form AuGa 2 .

[0030] In some embodiments, the gold source may be powdered gold, i.e., commercially available pure gold powder, for example, pure gold powder may be purchased from Alfa Aesar, CAS number: 7440-57-5, with a purity of 99.95%. Liquid gallium is a commercially available raw material, which may be purchased from Aladdin, CAS number: 7440-55-3, with a purity of 99.99%. Gallium may be slightly excessive, mainly for the following reasons: Gallium is liquid at room temperature and pressure, and can well fill the chamber and act as a pressurized medium.

[0031] In some embodiments, the reaction temperature is controlled to be 15°C-30°C, the reaction pressure is 0.1GPa-0.3GPa, and the reaction time is 1min-10min. 2 The new route for the compound can react at room temperature and extremely low pressure, without high temperature or arc melting, and the power consumption of the synthesis process is zero; the reaction time is very short, which is conducive to significantly improving production efficiency. Since high temperature conditions are not required and the need for argon atmosphere can be eliminated (anti-oxidation can be achieved without argon protection), the process cost can be greatly reduced.

[0032] It should be added that for small DACs used in laboratories, manual pressurization does not consume electricity; in industrial production, pressurization should consume electricity, but it is far less than thermal synthesis methods such as arc melting.

[0033] Specifically, the reaction temperature can be 15°C, 20°C, 25°C, 30°C, etc.; the reaction pressure can be 0.1 GPa, 0.2 GPa, 0.3 GPa, etc.; the reaction time can be 1 min, 3 min, 5 min, 8 min, 10 min, etc.

[0034] The reaction equipment is not limited, for example, a large cavity press can be used for production. The process provided by the embodiment of the present invention requires a very low pressure (<1 GPa, 1 GPa = 10000 atm). In contrast, the pressure required for industrial-grade artificial diamonds and cubic boron nitride (C-BN) produced using a large cavity press is 5-15 GPa. It can be seen that the method provided by the embodiment of the present invention can significantly reduce the operating pressure and is easy to control.

[0035] In some embodiments, a diamond anvil cell (DAC) can be used for the reaction. The raw material elements (powdered gold and liquid gallium) are mixed in a specified ratio and placed in the gasket hole of the diamond anvil cell, which is sealed in the diamond anvil cell to completely avoid the risk of oxidation during the synthesis process. Specifically, the diamond anvil cell is a standard device that can generate high pressure conditions, such as Figure 2As shown in (a), the reaction sample (a mixture of gold and gallium) is encapsulated in a gasket chamber and further sealed by two diamonds with parallel end faces facing each other. Ruby is used to indicate the pressure in the chamber. The principle is that the change in pressure will cause the shift of the characteristic peak of the R1 line in the fluorescence spectrum of ruby. The internal pressure of the chamber can be calculated according to the current position of this characteristic peak. Literature reference: Mao et al., Journal of Applied Physics. 49(6):3276–3283. (1978).

[0036] The material of the gasket can be rhenium, but not limited to this.

[0037] During the actual operation process, it can be operated in a glove box to avoid sample oxidation. Place the gold source and liquid gallium in the gasket hole of the diamond anvil, fill the gasket hole with liquid gallium, and react under pressurized conditions. Seal the hole of the gasket through two oppositely arranged diamonds, combined with Figure 3 , by adjusting the diamonds at both ends of the screw of the diamond anvil to approach each other, raise the pressure to the reaction pressure < 1 GPa (X-ray diffraction analysis shows that the initial pressure is about 0.2 ± 0.1 GPa).

[0038] As Figure 2 shown in (b), this figure is a real-shot picture of the reaction environment. The central area of the prepared sample is gallium, and pure gold powder is randomly distributed in the gallium liquid. At the same time, the position of the indicated ruby powder in the chamber is shown.

[0039] Furthermore, the dosage of liquid gallium can be greater than the theoretical dosage, and the specific dosage can be obtained according to the test equipment, such as according to the size of the hole of the gasket.

[0040] It should be noted that the present invention realizes environmentally friendly synthesis at almost zero cost (only raw materials are required). The costs of raw materials gold and gallium only account for a very small part of the terminal price of gold-based materials, and the main cost comes from the manufacturing process. It is expected that the method provided by the present invention can reduce the terminal cost of "blue gold" to less than 20% of the current price. Finally, the new path for synthesizing the AuGa 2 compound provided by the embodiments of the present invention can significantly reduce carbon dioxide emissions and related safety hazards while greatly reducing the relevant costs.

[0041] The embodiments of the present invention also provide an application of an AuGa 2 compound. The synthesis method provided by the embodiments of the invention has the advantages of low synthesis cost, environmental friendliness, etc. The AuGa 2 compound prepared by using this synthesis method can be further used to prepare jewelry or brazing materials, which has good application prospects.

[0042] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0043] It should be noted that the reaction equipment used in the following examples is as follows: Based on a commercially available diamond anvil (purchased from DACTools Co., Ltd., model BX-80), the diamond pair gaskets are pressed together vertically, forming a concave pit shape on the gasket, and laser drilling is performed on the thinner area (thickness of 50 microns) pressed out to form a chamber. The size of the formed chamber is 150 microns.

[0044] Example 1

[0045] This example provides a method for synthesizing an AuGa 2 compound, and the steps are as follows:

[0046] Powdery gold and liquid gallium are respectively added into the gasket holes of the diamond anvil. The molar ratio of gallium to gold is 5:1, and the liquid gallium fills the chamber. Ruby is used to indicate the pressure inside the chamber. By adjusting the screws of the diamond anvil, the two ends of the diamond are brought closer to each other, and the pressure is increased to the reaction pressure of about 0.2 ± 0.1 GPa. The reaction temperature is controlled at 20 °C, and the reaction time is 10 min.

[0047] Test Example 1

[0048] (1) After pressurization in Example 1, X-ray diffraction technology was used to detect the structure and chemical composition of the materials inside the diamond anvil, and the results are as Figure 4 shown.

[0049] Figure 4 The broadened peaks in originate from the unreacted excess gallium. The results clearly confirm that the AuGa 2 compound synthesized by this method is exactly the same as that synthesized by traditional techniques. The estimated synthesis pressure is about 0.2 GPa, and the compound remains stable after pressure release.

[0050] (2) The XRD patterns of the raw material samples in the synthesis method provided in Example 1 were recorded as the pressure changes (i.e., X-ray diffraction analysis was performed on different sites inside the sample chamber).

[0051] The results show that as the pressure increases, the gold content inside the sample chamber decreases rapidly. When the pressure exceeds 8 GPa, no signal from the gold element can be detected, indicating that even in the mixed area with a high gold content before the reaction, the gold therein is completely converted into AuGa 2 .

[0052] (3) The relationship between the unit cell volume of the synthesized AuGa 2 and the pressure change was measured, as Figure 5 shown.

[0053] Figure 5 It can be seen that the AuGa synthesized in the examples of the present invention2 The variation law of the unit cell volume of the compound with pressure is highly consistent with that of AuGa synthesized by traditional techniques 2 The existing research data (Baker et al., University of Nevada, Las Vegas, M.Sc. Thesis (2012) and Garg et al., J. Phys.: Condens. Matter 18 8523 (2006)) are highly consistent, further corroborating the successful synthesis of AuGa by this technology 2 synthesis

[0054] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention

Claims

1. A method for synthesizing an AuGa2 compound, characterized in that: include: Gold source and liquid gallium are used as raw materials, and liquid gallium is used as pressure medium, and the reaction is carried out under pressurized and closed conditions.

2. The synthesis method according to claim 1, characterized in that The reaction temperature is 15°C-30°C.

3. The synthesis method according to claim 1, characterized in that The reaction pressure is 0.1GPa-0.3GPa.

4. The synthesis method according to claim 1, characterized in that The reaction time is 1min-10min.

5. The synthesis method according to claim 1, characterized in that The gold source is powdered gold; and / or the amount of liquid gallium used is greater than the theoretical amount.

6. The synthesis method according to any one of claims 1 to 5, characterized in that include: The gold source and the liquid gallium are placed in the gasket hole of the diamond anvil, so that the liquid gallium fills the gasket hole and reacts under pressure.

7. The synthesis method according to claim 6, characterized in that The material of the gasket is rhenium.

8. The synthesis method according to claim 6, characterized in that The hole of the gasket is sealed by two diamonds arranged opposite to each other, and the pressure is increased to the reaction pressure by adjusting the pressure screw so that the diamonds at both ends are close to each other.

9. An AuGa2 compound, characterized in that It is prepared by the synthesis method according to any one of claims 1 to 8.

10. Use of the AuGa2 compound according to claim 9 in the preparation of jewelry or brazing materials.

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