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Phase transition, elastic and thermodynamical properties of TcC under high pressure from first‐principles calculations
Author(s) -
Zou YangChun,
Zhu Jun,
Hao YanJun,
Xiang Gang,
Liang XiaoChong,
Wang JinRong
Publication year - 2014
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.201350417
Subject(s) - debye model , bulk modulus , isochoric process , thermal expansion , thermodynamics , materials science , phase transition , shear modulus , enthalpy , elastic modulus , phase (matter) , condensed matter physics , chemistry , composite material , physics , organic chemistry
Phase transition, elastic and thermodynamical properties of technetium monocarbide (TcC) in the WC, NiAs, NaCl, CsCl, and ZnS structures have been studied by full‐potential linearized augmented‐plane‐wave (FP‐LAPW) theory. From the enthalpy difference between the five structures, we predict that the structural phase transition from WC‐type structure to CsCl‐type structure occurs at ca. 411.4 GPa. Meanwhile, it is found that the NiAs, NaCl, and ZnS types are not stable phases in whole pressure ranges considered. In particular, for the first time we calculate the elastic properties and phase transition of TcC under high pressures. For WC TcC and CsCl TcC structures, the elastic constants, bulk modulus, shear modulus, and Young's modulus are predicted to increase monotonically with increasing pressure. The Vickers hardness of TcC under high pressure is estimated. The brittle–ductile behavior of TcC has been obtained by Pugh's criteria. Finally, the Debye temperature, isochoric heat capacity and thermal expansion coefficient are predicted by the quasiharmonic Debye model method.