Low-temperature thermal properties of Fe-doped Co3Sn2S2

Recent studies on Co3Sn2S2 usually focus on its electrical and magnetic behaviors as it is a Weyl semimetal, half metal, and anisotropic ferromagnet at the same time. Only a few works looked into its low-temperature thermal characteristics. Here, we report the low-temperature heat capacity, Seebeck coefficient, and thermal conductivity of Fe-doped Co3Sn2S2, as well as the formation energies, band structures, and spin-polarized density of states calculated by using the spin-polarized relativistic Korringa-Kohn-Rostoker – Green’s function method (sprKKR). The heat capacity data reveal that the sample with a heavier Fe-doping level has a lower Debye temperature and a larger density of states at the Fermi level, the latter confirmed by our ab initio computational results. The Fe-doping increases the absolute value of the Seebeck coefficient at temperatures above 120 K and dramatically suppresses the thermal conductivity. Furthermore, we discuss how the external applied magnetic field affects the Seebeck coefficient and thermal conductivity of pristine Co3Sn2S2. Our findings provide a detailed reference and may stimulate future investigations into the low-temperature thermal transport properties of Co3Sn2S2 and other compounds in the shandite family.