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Elastic anisotropy and thermodynamic properties of chromium tetraboride from first‐principles calculations
Author(s) -
Xu Chao,
Liu Chunmei,
Duan Manyi,
Wang Haikuo
Publication year - 2015
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201552031
Subject(s) - debye model , anisotropy , bulk modulus , shear modulus , materials science , thermodynamics , thermal expansion , heat capacity , elastic modulus , young's modulus , chromium , condensed matter physics , composite material , metallurgy , physics , quantum mechanics
First‐principles calculations are performed to investigate the elastic anisotropy, and thermodynamic properties of chromium tetraboride (CrB 4 ) under extreme P – T conditions. The calculated equilibrium lattice and the normalized crystal parameters as a function of pressure are in good agreement with the available experimental and theoretical data. Elastic constants C ij are calculated in the pressure range of 0–50 GPa, and the bulk modulus B , shear modulus G , and Young's modulus E are also obtained according to the Voigt–Reuss–Hill (VRH) approximation. Anisotropic indexes are employed to characterize the mechanical anisotropy. The bulk modulus and Young's modulus as a function of crystal orientations are also investigated. The obtained results suggest that CrB 4 exhibits a pronounced elastic anisotropy. It is strongest along the b ‐axis in response to compression loading, and the {100} and {001} shear planes might be the cleavage planes. The elastic anisotropy of CrB 4 may possibly limit its applications. Using the quasiharmonic Debye model, thermodynamic properties like Debye temperature, Grüneisen parameter, heat capacity, and expansion coefficient are also systematically explored under extreme P – T conditions.