First-principles study on the elastic properties of Cu2GeSe3
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences - Ningbo 315201, China
Received: 1 September 2015
Accepted: 20 January 2016
The elastic properties of Cu2GeSe3, including bulk modulus, shear modulus, Young's modulus, Possion's ratio, and their anisotropic properties, have been investigated by using first-principles calculations. The calculated lattice parameters are in good agreement with previous calculations and experimental measurements. The result of bulk modulus by fitting the Birch-Murnaghan 3rd-order equation of state is well consistent with that calculated from the elastic constants. The ductile nature of Cu2GeSe3 is characterized according to Pugh's rule. The Debye temperature calculated from fitting heat capacity data is consistent with that obtained from sound velocity. Additionally, the elastic anisotropy is depicted in detail by plotting the directional dependence of the bulk and Young's moduli.
PACS: 62.20.D- – Elasticity / 65.40.Ba – Heat capacity / 63.20.dk – First-principles theory
© EPLA, 2016