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Elastic and Bandgap Modulations of Hexagonal BC 2 N From First‐Principles Calculations
Author(s) -
Li Shuaiqi,
Shi Liwei,
Zhu Haiyan,
Xia Wangsuo
Publication year - 2019
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.201900281
Subject(s) - debye model , materials science , elastic modulus , hydrostatic pressure , shear modulus , bulk modulus , anisotropy , condensed matter physics , band gap , ultimate tensile strength , vickers hardness test , young's modulus , phonon , composite material , thermodynamics , microstructure , optics , physics , optoelectronics
The structural, elastic, and electronic properties of a potential superhard material h‐BC 2 N as a function of external forces, including hydrostatic pressure and biaxial strains, are investigated using first‐principles calculations. For both types of external forces employed, the well qualified elastic criteria and positive phonon frequencies confirm its mechanical and dynamical stability. Considerable elastic constants and elastic modulus, especially Youngs modulus (965 GPa) and shear modulus (444 GPa), are obtained at equilibrium condition. All the elastic constants and elastic modulus increase (decrease) with increasing pressure and compressive (tensile)ϵ x xalong with a better (worse) ductile behavior. The theoretical Vickers hardness of h‐BC 2 N is 70.34 GPa, which is calculated from a microscopic determined model and increases notably with pressure and compressive strain. Debye temperature and elastic anisotropy of h‐BC 2 N are also included in this work, a sizeable Debye temperature of 2047K is obtained at ambient temperature. Besides, h‐BC 2 N is an indirect bandgap semiconductor with E g = 3.84 eV which can be slightly modulated by external forces.