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论文类型： 期刊论文

发表时间： 2012-03-01

发表刊物： DIAMOND AND RELATED MATERIALS

收录刊物： SCIE、EI

卷号： 23

页面范围： 44-49

ISSN号： 0925-9635

关键字： Amorphous; Carbon nitride; Bonding configurations; Hardness

摘要： Based on ab initio molecular dynamics method, four amorphous CNx, structures with different stoichiometries (CN0.47, CN0.67, CN0.92, and CN1.3) were generated within a 100-atom supercell. Characterizations of the pair correlation functions, bond length and the fraction of bond types of the amorphous carbon nitrides revealed that the N content in such structures plays a key role in determining the obtained structural networks. The calculations of the cohesive energy give direct evidence that experimentally synthesized amorphous carbon nitride films usually possess low nitrogen concentration. The competition relationship between sp(2) and sp(3) bonds was analyzed by electronic effect and electron density of states. The bonding states, especially the sp(3), affect greatly the hardness of these a-CNx compounds, implying a possible way to enhance the hardness of films via tuning the bonding states. (C) 2011 Elsevier B.V. All rights reserved.