Preparation method of large-size and high-performance lanthanum hexaboride single crystals

A lanthanum hexaboride, large-size technology, applied in the field of preparation of lanthanum hexaboride single crystal, can solve the problem of small size of lanthanum hexaboride single crystal, and achieve good performance and high quality

Active Publication Date: 2018-05-18
安徽尚欣晶工新材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem of the small size of the existing lanthanum hexaboride single crystal sample, the present invention aims to provide a method for preparing a large-sized, high-performance lanthanum hexaboride single crystal

Method used

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  • Preparation method of large-size and high-performance lanthanum hexaboride single crystals
  • Preparation method of large-size and high-performance lanthanum hexaboride single crystals
  • Preparation method of large-size and high-performance lanthanum hexaboride single crystals

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Embodiment 1

[0037] The present invention combines spark plasma sintering technology and optical region melting technology to prepare large-size, high-quality lanthanum hexaboride single crystal, including the following steps:

[0038] Step 1, polycrystalline block preparation

[0039] The lanthanum hexaboride powder with a purity of 99.9% was ball-milled in an Ar atmosphere for 2 hours so that the particle size of the powder was ≤2 μm; then the ball-milled powder was put into a graphite mold, and the graphite mold was placed in a spark plasma sintering furnace (LABOX- 350), sintering under vacuum conditions to obtain lanthanum hexaboride sintered polycrystalline rods;

[0040] The sintering process parameters are set as: heating rate 100-300°C / min (after many experiments, any value within this range can be achieved), pressure 30-50MPa (after many experiments, any value within this range can be achieved), the sintering temperature is 1300-1800°C (after many experiments, any value within t...

Embodiment 2

[0058] The present invention combines spark plasma sintering technology and optical region melting technology to prepare large-size, high-quality lanthanum hexaboride single crystal, including the following steps:

[0059] Step 1, polycrystalline block preparation

[0060] Ball-mill lanthanum hexaboride powder with a purity of 99.9% in an Ar atmosphere for 2 hours so that the particle size of the powder is ≤2 μm; then put the ball-milled powder into a graphite mold, and place the graphite mold in a spark plasma sintering furnace (LABOX-350), sintered under vacuum conditions to obtain lanthanum hexaboride sintered polycrystalline rods;

[0061] The sintering process parameters are set as: heating rate 100-300°C / min (after many experiments, any value within this range can be achieved), pressure 30-50MPa (after many experiments, any value within this range can be achieved), the sintering temperature is 1300-1800°C (after many experiments, any value within this range can be achie...

Embodiment 3

[0079] The present invention combines spark plasma sintering technology and optical region melting technology to prepare large-size, high-quality lanthanum hexaboride single crystal, including the following steps:

[0080] Step 1, polycrystalline block preparation

[0081] Ball-mill lanthanum hexaboride powder with a purity of 99.9% in an Ar atmosphere for 2 hours so that the particle size of the powder is ≤2 μm; then put the ball-milled powder into a graphite mold, and place the graphite mold in a spark plasma sintering furnace (LABOX-350), sintered under vacuum conditions to obtain lanthanum hexaboride sintered polycrystalline rods;

[0082] The sintering process parameters are set as: heating rate 100-300°C / min (after many experiments, any value within this range can be achieved), pressure 30-50MPa (after many experiments, any value within this range can be achieved), the sintering temperature is 1300-1800°C and any value within this range can be achieved after many experi...

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Abstract

The invention discloses a preparation method of large-size and high-performance lanthanum hexaboride single crystals. A discharge plasma sintering technology and an optical region smelting technologyare combined, firstly, a zone melting polycrystal is prepared at a higher growth rate, the lanthanum hexaboride single crystals with uniform diameter and size larger than or equal to 10 mm are prepared at a lower growth rate on the basis of the single crystals as seed crystals. The prepared lanthanum hexaboride single crystals have the diameter larger than that reported in all existing literaturesand have high quality and good performance, and a foundation for further engineering application of the single crystals is laid.

Description

technical field [0001] The invention belongs to the technical field of cathode material preparation, and in particular relates to a preparation method of lanthanum hexaboride single crystal. Background technique [0002] Lanthanum hexaboride (LaB 6 ) has high brightness, low work function, low evaporation rate, strong resistance to ion bombardment, and large emission current density. Machines and other large precision equipment fields have very broad application prospects. After more than half a century of development, extensive and in-depth research has been carried out on the structure, physical and chemical properties of lanthanum hexaboride and related cathodes, and a variety of preparation technologies have also been formed, including sintering technology, chemical vapor deposition, aluminum solvent method and regional Melting technology. Sintering technology is mainly used to prepare large-sized polycrystalline bulk samples, and the current density is relatively sma...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/10C30B13/00
CPCC30B13/00C30B29/10
Inventor 张久兴杨新宇王衍赵晶晶李志
Owner 安徽尚欣晶工新材料科技有限公司
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