First-principles calculation of transition-metal Seebeck coefficients

Abstract

The Korringa--Kohn--Rostoker (KKR) method combined with the coherent potential approximation (CPA; KKR-CPA) and linear response theory is applied to first-principles calculation of the Seebeck coefficients of pure metals. The main objective is to develop a practical first-principles scheme that can calculate the conductivities and Seebeck coefficients of metallic systems at finite temperature. Thus, it is necessary to include the effects of electron-phonon scattering, which plays a crucial role at finite temperature, particularly for ordered-structure systems where the conductivity diverges at T=0 K. The approach combines three components: linear response theory in the framework of the KKR method; phonon calculations; and an alloy analogy applied to the local static phonons using the KKR-CPA. The calculated Cu resistivity and Seebeck coefficients for various transition-metal elements at finite temperature show reasonably good overall agreement with experiment.  The present approach provides a framework applicable to a wide range of materials, including pure metals, compounds, doped semiconductors, ordered and disordered alloys, opening up the possibilities of computational design of useful thermoelectric materials.