燕山大学学报2013，Vol.37Issue(1)：22-26,5.DOI:10.3969/j.issn.1007-791X.2013.01.004
新型立方碳的第一性原理研究
First principles study on a novel cubic carbon
摘要
Abstract
A novel cubic carbon (termed as sc-C20 with a=4.886 (A)) is proposed through employing the newly developed particle swarm optimization (PSO) algorithm.Furthermore, the properties and possible synthesis methods are investigated.The sc-C20 is metastable under ambient pressure, and is more stable than graphite at high-pressure (>100 GPa), indicating that it can be synthesized through high-pressure.The similarity of the lattice parameters and d-spacing between sc-C20 i-carbon with a=4.86 A, implies that the former can be achieved through chemical methods.Electronic band structure calculations show that sc-C20 is a semiconductor with wide band gap of 4.20 eV, and the gap increase with pressure, similar to that of diamond.The sc-C20 has high bulk and shear moduli, and the Vickers hardness is 94.4 GPa, comparable with that of diamond, indicative of superhard nature.The tensile strength of sc-C20 is low, and the highest strength is 96.4 GPa along <111> direction.关键词
第一性原理/立方碳/超硬/宽带隙/i-碳Key words
first principle/ cubic carbon/ superhardness/ wide band gap/ i-carbon分类
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胡盟,程杰,何巨龙..新型立方碳的第一性原理研究[J].燕山大学学报,2013,37(1):22-26,5.基金项目
国家自然科学基金资助项目(51272227) （51272227）
