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Updated: May 22, 2025

$Synthesis and Microdiffraction at Extreme Pressures and Temperatures$

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

Published on: October 7, 2013

从石墨中直接合成一毫米大小的六角形钻石

Xiaohong Yuan¹, Guwen Chen², Yong Cheng³

¹State Key Laboratory of High Pressure and Superhard Materials, Synergetic Extreme Condition High-Pressure Science Center, College of Physics, Jilin University, Changchun 130012, China.

Science bulletin

|March 13, 2025

概括

研究人员使用一种新的高压技术从石墨中合成了大型六角形钻石. 这种超硬材料比立方钻石更硬,通过马氏体转化形成,为相变提供了新的见解.

科学领域:

材料科学材料科学材料科学
地质物理学地质物理学
固态物理固态物理

背景情况:

钻石的立方体结构在高压下稳定,限制了其多态的合成.
六角形钻石是一种多态体,难以合成纯大型,阻碍了性能和机制研究.

研究的目的:

报告毫米大小,几乎纯粹的六角钻石的直接合成.
为了研究合成的六角钻石的形成机制和特性.
为了探索石墨的高压相变.

主要方法:

开发了一种使用多压机的高压技术.
在高压和高温条件下从石墨中合成六角形钻石.
采用结构特征和分子动力学模拟.

主要成果:

实现了毫米尺寸,几乎纯的六角形钻石的直接合成.
合成的六角形钻石表现出超硬度 (165 ± 4 GPa),超过单晶立方钻石约50%.
确定了一种马氏体转化过程,涉及石墨板的滑动和粘合,以形成六边形钻石.
证明了石墨对立方形/六角形钻石转换的温度-压力依赖.
合成的立方体/六角形钻石复合材料,在较低的压力下具有新的异构结构.

结论:

在石墨中建立了高压相变的框架.
提供了对高压下二维材料结构演变的见解.
开发了一种探索材料新高压相的策略.

关键词:

石墨石墨是一种石墨.有六角形的钻石.高压的高压的高压.模拟MD的模拟方法阶段转换阶段转换

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