Ferromagnetic ordering and half-metallic state of Sn2Co3S2 with the shandite-type structure

Single crystalline Sn2Co3S2 with the shandite-type structure was investigated by magnetization, magnetoresistance, Hall effect, and heat capacity measurements and by Sn-119 Mossbauer spectroscopy. Sn2Co3S2 orders ferromagnetically at 172 K with an easy-axis magnetization of approximate to 1 mu(B) along the hexagonal c axis. The half-metallic ferromagnetic state is investigated by detailed band-structure calculations by density functional theory (DFT) methods. The magnetoresistance and the Hall effect as well as the DFT results show that ferromagnetic Sn2Co3S2 is a compensated metal. The Sn-119 Mossbauer spectroscopic data confirm these findings. Large transferred hyperfine fields B-hf up to 34.2 T are observed.