Ab initio calculations on the structural and lattice dynamical properties of TmX (X=As, P) compounds

作者：Coban C^*; Colakoglu K; Ciftci Y O

来源：Journal of Physics and Chemistry of Solids, 2012, 73(7): 917-924.

DOI：10.1016/j.jpcs.2012.02.026

• Ab initio calculations
• Elastic properties
• Thermodynamic properties
• Lattice dynamics

The structural and lattice dynamical properties of TmX (X=As, P) compounds were investigated using normconserving pseudopotentials within the generalized gradient approximation correction (GGA) of Perdew-Burke-Ernzerhof (PBE) in the framework of density functional theory (DFT). The structural parameters (a(o), B, B%26apos;, E-coh) were determined through total energy and interatomic force minimization and the overall agreement was found to be good. The pressure dependence of the ratios of normalized lattice parameters a/a(o), normalized volume V/V-o, bulk modulus, elastic constants, Zener anisotropy factor, Poisson%26apos;s ratio, Young%26apos;s modulus, shear modulus, and the brittleness were presented and discussed. The thermodynamical properties such as thermal expansion, heat capacity, Debye temperature, and Gruneisen parameter were calculated employing the quasi-harmonic Debye model at different temperatures (0-1000 K) and pressures (0-30 GPa). The phonon dispersion curves and corresponding density of states (DOS) of TmX (X=As, P) were also obtained, and the salient results were interpreted.

• 出版日期2012-7