A powder neutron diffraction study of the metallic ferromagnet Co₃Sn₂S₂

Variable-temperature powder neutron diffraction data reveal that Co₃Sn₂S₂ crystallizes in the shandite structure (space group R over(3, -) m, a = 5.36855(3) Å, c = 13.1903(1) Å at 300 K). The structural relationship between Co₃Sn₂S₂ and the intermetallic compound CoSn, both of which contain Kagomé nets of cobalt atoms, is discussed. Resistivity and Seebeck coefficient measurements for Co₃Sn₂S₂ are consistent with metallic behaviour. Magnetic susceptibility measurements indicate that Co₃Sn₂S₂ orders ferromagnetically at 180(10) K, with a saturation moment of 0.29 µ_B per cobalt atom at 5 K. The onset of magnetic ordering is accompanied by marked anomalies in the electrical transport properties. © 2008 Elsevier Masson SAS. All rights reserved.