摘要
现有材料的硬度可用硬度计来测量。从理论上严格计算硬度值是一件困难的事情。但随着超硬材料理论设计的蓬勃发展,硬度的预测成为一个瓶颈问题。本文系统介绍了利用复杂晶体化学键理论计算晶体硬度的基本理论,以及关于纳米晶硬度的计算方法。利用第一性原理几何优化方法建立了新近合成的具有氧缺陷的四方BC2N相的晶体结构。利用硬度理论预测了它的硬度。结果表明该物质是一个超硬半导体材料。
The theory of hardness based on the theory of chemical bond of complex crystals and the calculating method of hardness of nano-crystals was introduced systemically . First principles techniques were employed to investigate the structural, elastic, mechanical and eletronic properties of the tetragonalstructured BC2N phase with oxygen-bearing defects, Results confirm that the as-prepared sample is superlattice phase of β-BC2N phase with defects of the CN′ and the ON^.. And it is a semiconductor material with direct energy band gap 1.21 eV. The calculated hardness is comparable to that of diamond.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2008年第5期1136-1140,1171,共6页
Journal of Synthetic Crystals
基金
国家自然科学基金(No.50472050
50672080)
教育部新世纪优秀人才支持计划
全国优秀博士学位论文作者基金(No.200434)
人事厅留学人员基金
关键词
硬度
化学键
纳米晶
第一性原理
hardness
chemical bond
nano-crystal
first principle
