First-principles study of the thermoelectric properties of SrRuO₃

The Seebeck coefficient, thermoelectric power factor, electrical conductivity, and electronic thermal conductivity of the orthorhombic Pbnm phase of SrRuO₃ are studied comprehensively by combining first-principles density functional calculations and Boltzmann transport theory. The influence of exchange-correlation functional on the Seebeck coefficient is carefully investigated. We show that the best agreement with experimental data is achieved when SrRuO₃ is described as being at the limit of a half-metal. Furthermore, we analyze the role of individual symmetry-adapted atomic distortions on the Seebeck coefficient, highlighting a particularly strong sensitivity to R4⁺ oxygen rotational motions, which may shed light on how to manipulate the Seebeck coefficient. We confirm that the power factor of SrRuO₃ can only be slightly improved by carrier doping. Our results provide a complete understanding of the thermoelectric properties of SrRuO₃ and an interesting insight on the relationship between exchange-correlation functionals, atomic motions, and thermoelectric quantities.