Condensed Matter Physics, 2012, vol. 15, No. 1, 13603: 19
DOI:10.5488/CMP.15.13603
arXiv:1204.5824
Title:
Elastic and electronic properties of fluorite RuO_{2} from first principle
Author(s):

Z.J. Yang
(School of Science, Zhejiang University of Technology, Hangzhou, 310023, China )
,


A.M. Guo
(Department of Physics, California State University, Northridge, California 913308268, USA )
,


Y.D. Guo
(School of Physics, Neijiang Normal University, Neijiang, 641112, China )
,


J. Li
(College of Material and Chemical Engineering, Hainan Provincial Key Laboratory of Research on Utilization of SiZrTi Resources, Hainan University, Haikou, 570228, China )
,


Z. Wang
(College of Material and Chemical Engineering, Hainan Provincial Key Laboratory of Research on Utilization of SiZrTi Resources, Hainan University, Haikou, 570228, China )
,


Q. Liu
(School of Physics, Chongqing University of Technology, Chongqing, 400050, China )
,


R.F. Linghu
(School of Physics, Guizhou Normal University, Guiyang, 550001, China )
,


X.D. Yang
(Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065, China )

The elastic, thermodynamic, and electronic properties of fluorite RuO_{2} under high pressure are investigated by planewave pseudopotential density functional theory. The optimized lattice parameters, elastic constants, bulk modulus, and shear modulus are consistent with other theoretical values. The phase transition from modified fluoritetype to fluorite is 88 GPa (by localized density approximation, LDA) or 115.5 GPa (by generalized gradient approximation, GGA). The Young's modulus and Lamé's coefficients are also studied under high pressure. The structure turned out to be stable for the pressure up to 120 GPa by calculating elastic constants. In addition, the thermodynamic properties, including the Debye temperature, heat capacity, thermal expansion coefficient, Grüneisen parameter, and Poisson's ratio, are investigated. A small band gap is found in the electronic structure of fluorite RuO_{2} and the bandwidth increases with the pressure. Also, the present mechanical and electronic properties demonstrate that the bonding nature is a combination of covalent, ionic, and metallic contributions.
Key words:
first principle, electronic structure, elasticity, thermodynamicity
PACS:
63.20.dk, 71.20.b, 62.20.D, 65.40.b
