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Indexed by:期刊论文

Date of Publication:2012-03-01

Journal:DIAMOND AND RELATED MATERIALS

Included Journals:SCIE、EI

Volume:23

Page Number:44-49

ISSN No.:0925-9635

Key Words:Amorphous; Carbon nitride; Bonding configurations; Hardness

Abstract: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.