Dependence of spin states on thermoelectric quantities in a single-layer FeCl₂

Abstract Some thermoelectric quantities were considered under the spin states, i.e., spin-up and spin-down states, in a single-layer FeCl 2 . It covers the Seebeck coefficient, electrical and thermal conductivities, and figure of merit. We first examined the band structure for the spin-up and spin-down states based on density functional theory in the collinear ferromagnetic state. From the separated energy states, the Seebeck coefficients were computed under the Boltzmann transport theory. We found that only the spin-down state, which creates a metallic state, contributes to the thermoelectric performance. Even though the peak of the figure of merit is far from the Fermi level, this can be shifted by doping.