中国物理B ›› 2012, Vol. 21 ›› Issue (6): 67101-067101.doi: 10.1088/1674-1056/21/6/067101

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Theoretical investigation on the electronic structure, elastic properties, and intrinsic hardness of Si2N2O

丁迎春, 陈敏, 高秀英, 蒋孟衡   

  1. College of Optoelectronics Technology, Chengdu University of Information Technology, Chengdu 610225, China
  • 收稿日期:2011-09-08 修回日期:2011-12-07 出版日期:2012-05-01 发布日期:2012-05-01

Theoretical investigation on the electronic structure, elastic properties, and intrinsic hardness of Si2N2O

Ding Ying-Chun(丁迎春)†, Chen Min(陈敏), Gao Xiu-Ying(高秀英), and Jiang Meng-Heng(蒋孟衡)   

  1. College of Optoelectronics Technology, Chengdu University of Information Technology, Chengdu 610225, China
  • Received:2011-09-08 Revised:2011-12-07 Online:2012-05-01 Published:2012-05-01
  • Contact: Ding Ying-Chun E-mail:dyccqzx@yahoocom.cn

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摘要： According to the density functional theory we systematically study the electronic structure, the mechanical properties and the intrinsic hardness of Si2N2O polymorphs using the first-principles method. The elastic constants of four Si2N2O structures are obtained using the stress-strain method. The mechanical moduli (bulk modulus, Young's modulus, and shear modulus) are evaluated using the Voigt-Reuss-Hill approach. It is found that the tetragonal Si2N2O exhibits a larger mechanical modulus than the other phases. Some empirical methods are used to calculate the Vickers hardnesses of the Si2N2O structures. We further estimate the Vickers hardnesses of the four Si2N2O crystal structures, suggesting all Si2N2O phases are not the superhard compounds. The results imply that the tetragonal Si2N2O is the hardest phase. The hardness of tetragonal Si2N2O is 31.52 GPa which is close to values of β-Si3N4 and γ-Si3N4.

关键词: elastic property, Vickers hardness, electronic structure

Abstract: According to the density functional theory we systematically study the electronic structure, the mechanical properties and the intrinsic hardness of Si2N2O polymorphs using the first-principles method. The elastic constants of four Si2N2O structures are obtained using the stress-strain method. The mechanical moduli (bulk modulus, Young's modulus, and shear modulus) are evaluated using the Voigt-Reuss-Hill approach. It is found that the tetragonal Si2N2O exhibits a larger mechanical modulus than the other phases. Some empirical methods are used to calculate the Vickers hardnesses of the Si2N2O structures. We further estimate the Vickers hardnesses of the four Si2N2O crystal structures, suggesting all Si2N2O phases are not the superhard compounds. The results imply that the tetragonal Si2N2O is the hardest phase. The hardness of tetragonal Si2N2O is 31.52 GPa which is close to values of β-Si3N4 and γ-Si3N4.

Key words: elastic property, Vickers hardness, electronic structure

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
71.20.-b (Electron density of states and band structure of crystalline solids) 62.20.-x (Mechanical properties of solids) 62.20.Qp (Friction, tribology, and hardness)