Synthesis, crystal structure and physical properties of the thulium filled skutterudite TmFe4P12 under the effect of the pressure: LDA and LSDA calculation

Ab-initio study of structural, electronic, elastic and thermodynamic, properties of the filled skutterudite TmFe4P12 has been reported using the FP-LMTO method with the local density approximation (LDA) and the local spin-density approximation (LSDA). The computed equilibrium lattice constants are an excellent agreement with the experimental data. The electronic band structure and densities of states profiles show that the studied compound is conductors. The elastic constants, the bulk modulus B, anisotropy factor A, shear modulus G, young's modulus E, Poisson's ratio ν and the ratio B/G for TmFe4P12 compound with pressure in the ranges 0–50 GPa are obtained. The sound velocities and Debye temperature are also predicted from elastic constants. Finally, the variations of the primitive cell volume, expansion coefficient α, bulk modulus B, heat capacity (Cp and Cv), Debye temperature θD, Helmholtz free energy A, Gibbs free energy G, entropy S, and internal energy U with pressure and temperature in the ranges of 0–50 GPa and 0–3000 K are obtained successfully.