Analysis of mechanical, thermodynamic, and thermoelectric properties of ferromagnetic SrFe4As12 skutterudite

Abstract

In the present work, the electronic, mechanical, thermal and thermoelectric properties of Sr-filled skutterudite have been investigated in the framework of density functional theory. SrFe4As12 shows a ferromagnet character with a magnetic moment of 1.76 μB at an optimized lattice parameter of 8.38 Å. The effect of high-pressures on thermodynamic properties viz. thermal expansion coefficient, specific heat capacity and Grüneisen parameter is also carried out by employing the quasi-harmonic Debye model. Temperature dependence of Seebeck coefficient, electrical conductivity, thermal conductivity, power factor, and figure of merit is observed up to 800 K. The lattice thermal conductivity decreases with temperature due to rattling behavior of the filler atom. SrFe4As12 exhibits the high value of the figure of merit equal to 0.76 at 800 K. The present results clearly signify that SrFe4As12 may be a good choice for thermoelectric applications due to its high-power factor and figure of merit.