Method for preparing AlN at low temperature based on aluminum-containing precursor and AlN material

Abstract

The invention discloses a method for preparing AlN at a low temperature based on an aluminum-containing precursor and an AlN material, and the method comprises the following steps: keeping the aluminum-containing precursor in a mixed atmosphere of ammonia gas and chlorine-containing organic gas at 1000-1400 DEG C for 0.5-10 hours to react, and obtaining the AlN material after the reaction is finished, and the chlorine-containing organic matter is selected from at least one of CCl4, CHCl3, CH2Cl2 or CH3Cl. Based on the similarity between an aluminum-containing precursor and an AlN crystal structure, under the auxiliary action of a chlorine-containing organic matter, the aluminum-containing precursor can react with NH3 at a low temperature to prepare high-crystallinity AlN.

Description

Technical Field

[0001] The invention belongs to the field of metal nitride material preparation, and particularly relates to a method for preparing AlN based on an aluminum-containing precursor at low temperature and an AlN material. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] AlN has the characteristics of high thermal conductivity, small thermal expansion coefficient, low dielectric loss, anti-electromagnetic radiation and excellent optical properties. It is a raw material for electronic packaging materials and ceramic substrate materials with excellent heat dissipation performance. It has a wide range of applications in many fields such as electronics, automobiles, aviation and defense, medical treatment, and chemical industry. At present, the preparation of AlN is mainly obtained by carbon thermal reduction and chemical vapor synthesis, which usually requires complex processing technology and extremely high calcination temperature (usually higher than 1600°C), and the prepared AlN grain size is usually large, which is not conducive to subsequent practical applications.

[0004] In addition, the carbon thermal reduction method, which is already a method for large-scale production in the industry, not only requires a temperature of over 1600°C to synthesize, but also excessive or insufficient C content will affect the performance of AlN. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a method for preparing AlN at low temperature based on an aluminum-containing precursor and an AlN material. Based on the similarity between the aluminum-containing precursor and the AlN crystal structure, the present invention can react with NH4+ at a relatively low temperature with the assistance of chlorine-containing organic matter. 3 The reaction produces highly crystalline AlN.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing AlN at low temperature based on an aluminum-containing precursor, comprising the following steps:

[0008] The aluminum-containing precursor is reacted in a mixed atmosphere of ammonia and chlorine-containing organic gas at 1000-1400° C. for 0.5-10 hours. After the reaction is completed, the product is obtained.

[0009] The role of ammonia is to provide a nitrogen source to nitride the oxide; the role of chlorine-containing organic gas is to promote the nitridation reaction, so that AlN can be prepared under low temperature conditions.

[0010] In some embodiments, the aluminum-containing precursor is selected from LiAlO 2 、NaAlO 2 , KAlO 2、AlOOH、α-Al 2 O 3 or γ-Al 2 O 3 .

[0011] The chlorine-containing organic compound is selected from CCl 4 , CHCl 3 , CH 2 Cl 2 or CH 3 At least one of Cl.

[0012] In some embodiments, an inert gas (N 2 ,Ar 2 ) is used as a carrier gas to blow the chlorine-containing organic matter in a Monterey bottle into the reaction system, and the carrier gas flow rate is controlled at 50-500 sccm.

[0013] Preferably, the volatilization amount of the chlorine-containing organic matter is controlled by controlling the temperature and the carrier gas flow rate. The chlorine-containing organic matter is placed in a Monterey bottle and placed in a circulating cooling water bath, and the circulating water bath temperature is controlled at 0-50°C.

[0014] In some embodiments, in the mixed atmosphere of ammonia gas and chlorine-containing organic gas, the volume ratio of ammonia gas to chlorine-containing organic gas is 1:10 to 10:1.

[0015] In some embodiments, the heating rate of the reaction process is 1-20° C. / min.

[0016] In some embodiments, an aluminum-containing precursor is placed in a crucible, put into a tube furnace, and after evacuation, a mixed gas of ammonia and chlorine-containing organic gas is introduced.

[0017] Preferably, the crucible is a corundum crucible or a quartz crucible.

[0018] In a second aspect, the present invention provides an AlN material prepared by the preparation method.

[0019] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0020] The technical solution provided by the present invention can obtain pure phase AlN at a relatively low calcination temperature (1000-1400°C), which greatly reduces the calcination temperature of traditional AlN preparation. The preparation method is simple, only one calcination is required, and the obtained AlN particles have small and uniform particle size. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 This is a field emission scanning electron microscope image of the aluminum nitride prepared in Example 1;

[0023] Figure 2 The XRD diffraction pattern of aluminum nitride prepared in Example 1;

[0024] Figure 3 This is a field emission scanning electron microscope image of the aluminum nitride prepared in Example 2;

[0025] Figure 4 The XRD diffraction pattern of aluminum nitride prepared in Example 2;

[0026] Figure 5 This is a field emission scanning electron microscope image of the aluminum nitride prepared in Example 3;

[0027] Figure 6 This is the XRD diffraction pattern of aluminum nitride prepared in Example 3. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] The present invention will be further described below in conjunction with the embodiments.

[0030] Example 1

[0031] (1) Take 0.5g NaAlO 2 The powder was placed in a corundum crucible, which was then placed in a tube furnace and sealed. After the tube furnace was evacuated, NH 3 and CHCl 3 The mixed airflow, NH 3 The flow rate of CHCl was maintained at 200 sccm. 3 Place in a Monterey bottle and put in a cooling circulating water bath, keep the water temperature at 10°C, then blow in nitrogen at a flow rate of 100 sccm. After the gas flow stabilizes, heat the tube furnace to 1100°C at a heating rate of 5°C / min and keep at this temperature for 4 hours. After the reaction is completed and the tube furnace is naturally cooled to room temperature, take out the final product.

[0032] (2) The morphology and particle size of the product were analyzed by field emission scanning electron microscopy (SEM, Hitachi S-4800). Figure 1 As shown; the phase of the product was analyzed by X-ray powder diffractometer (Bruker AXSD8 advanced), as shown Figure 2shown.

[0033] Example 2

[0034] (1) Take 3g α-Al 2 O 3 The powder was placed in a corundum crucible, which was then placed in a tube furnace and sealed. After the tube furnace was evacuated, NH 3 and CH 2 Cl 2 The mixed airflow, NH 3 The flow rate of CH was maintained at 100 sccm. 2 Cl 2 Place in a Monterey bottle and put in a cooling circulating water bath, keep the water temperature at 0°C, then blow in nitrogen at a flow rate of 500sccm. After the gas flow stabilizes, heat the tube furnace to 1000°C at a heating rate of 5°C / min and keep at this temperature for 10 hours. After the reaction is completed and the tube furnace is naturally cooled to room temperature, take out the final product.

[0035] (2) The morphology and particle size of the product were analyzed by field emission scanning electron microscopy (SEM, Hitachi S-4800). Figure 3 As shown; the phase of the product was analyzed by X-ray powder diffractometer (Bruker AXSD8 advanced), as shown Figure 4 shown.

[0036] Example 3

[0037] (1) Take 10g γ-Al 2 O 3 The powder was placed in a corundum crucible, which was then placed in a tube furnace and sealed. After the tube furnace was evacuated, NH 3 and CCl 4 The mixed airflow, NH 3 The flow rate of CCl was maintained at 400 sccm. 4 Place in a Monterey bottle and put in a cooling circulating water bath, keep the water temperature at 40°C, then blow in argon gas at a flow rate of 50 sccm. After the gas flow stabilizes, heat the tube furnace to 1300°C at a heating rate of 10°C / min and keep at this temperature for 1 hour. After the reaction is completed and the tube furnace is naturally cooled to room temperature, take out the final product.

[0038] (2) The morphology and particle size of the product were analyzed by field emission scanning electron microscopy (SEM, Hitachi S-4800). Figure 5 As shown; the phase of the product was analyzed by X-ray powder diffractometer (Bruker AXSD8 advanced), as shown Figure 6 shown.

[0039] pass Figure 1 It can be seen that NaAlO 2 In CHCl 3 With the assistance of NH 3 The AlN particles synthesized by the reaction have a particle size between 500nm and 2μm. Figure 3 It can be seen that α-Al 2 O 3 In CH 2 Cl 2 With the auxiliary effect, 3 The particle size of AlN particles synthesized by the reaction is about 100nm, and the particle distribution is relatively uniform. Figure 5 As shown, γ-Al 2 O 3 In CCl 4 The AlN synthesized by reaction with NH3 with the assistance of NH4 has a particle size between 200nm and 600nm. Figure 2 , Figure 4 and Figure 6 The XRD results show that all the peaks are AlN crystal plane diffraction peaks, and there are no other impurity peaks, which proves that the AlN prepared by this method is pure phase.

[0040] In summary, through NaAlO 2 In CHCl 3 With the assistance of NH 3 AlN powder can be obtained by reaction at 1100℃; 2 O 3 In CH 2 Cl 2 With the assistance of NH 3 AlN powder can be obtained by reaction at 1000℃; 2 O 3 In CCl 4 With the assistance of NH 3 The reaction can produce AlN powder at 1300°C, and the method has the advantage of a simple preparation process. Compared with the calcination temperature of traditional AlN synthesis, which mostly exceeds 1600°C, the technical solution provided by the present invention effectively reduces the calcination temperature of AlN, can save energy, and provides a new method for low-temperature preparation of AlN.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing AlN at low temperature based on an aluminum-containing precursor, characterized in that: The steps include: The aluminum-containing precursor is placed in a mixed atmosphere of ammonia and chlorine-containing organic gas at 1000-1400°C for 0.5-10 hours for reaction. After the reaction is completed, the product is obtained. The chlorine-containing organic matter is selected from at least one of CCl4, CHCl3, CH2Cl2 or CH3Cl.

2. The method for preparing AlN based on an aluminum-containing precursor at low temperature according to claim 1, characterized in that: The aluminum-containing precursor is selected from LiAlO2, NaAlO2, KAlO2, AlOOH, α-Al2O3 or γ-Al2O3.

3. The method for preparing AlN based on an aluminum-containing precursor at low temperature according to claim 1, characterized in that: In the mixed atmosphere of ammonia gas and chlorine-containing organic gas, the volume ratio of ammonia gas to chlorine-containing organic gas is 1:10 to 10:

1.

4. The method for preparing AlN based on an aluminum-containing precursor at low temperature according to claim 1, characterized in that: Using inert gas as carrier gas, the chlorine-containing organic matter in the Mengshi washing bottle is blown into the reaction system, and the carrier gas flow rate is 50-500sccm.

5. The method for preparing AlN at low temperature based on an aluminum-containing precursor according to claim 4, characterized in that: The chlorine-containing organic matter is placed in a Monterey bottle, and the Monterey bottle is placed in a circulating cooling water bath.

6. The method for preparing AlN at low temperature based on an aluminum-containing precursor according to claim 5, characterized in that: The temperature of the chlorine-containing organic matter is between 0 and 50°C.

7. The method for preparing AlN at low temperature based on an aluminum-containing precursor according to claim 1, characterized in that: The heating rate of the reaction process is 1-20°C / min.

8. The method for preparing AlN at low temperature based on an aluminum-containing precursor according to claim 1, characterized in that: The aluminum-containing precursor is placed in a crucible, put into a tube furnace, and after vacuuming, a mixed gas of ammonia and chlorine-containing organic gas is introduced.

9. The method for preparing AlN at low temperature based on an aluminum-containing precursor according to claim 8, characterized in that: The crucible is a corundum crucible or a quartz crucible.

10. An AlN material, characterized in that: Prepared by the preparation method described in any one of claims 1 to 9.

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