Spin Seebeck effect driven by thermal flux in two-dimensional ferromagnets

Abstract

The spin Seebeck effect is a novel indirect thermoelectric conversion phenomenon, in which magnetic materials play an important role, that is distinct from the traditional direct thermoelectric conversion method. In this paper, we studied the spin Seebeck effect driven by thermal flux in two-dimensional ferromagnets and derived the spin-dependent Seebeck coefficient and the spin Seebeck coefficient contributed by conduction electrons in a ferromagnet based on the non-equilibrium linear irreversible thermodynamics and the Boltzmann linear theory. The spin Seebeck coefficients of six two-dimensional ferromagnetic materials (including manganese halides and transition metal chalcogenides) were numerically calculated. A largest spin Seebeck coefficient is found for MnCl 3 to be 1600 μV/K in the range of temperature from 50 to 120 K, which is even larger than that of known CrI 3 and CrGeTe 3. The present study on the heat flow-spin current transport properties of ferromagnets could have great significance for the thermoelectric applications in spintronics.