Magnetic and crystal structure of Th–Fe–Sn intermetallics: ThFe0.22Sn2 and Th4Fe13Sn5

The crystal and magnetic structures of two new ternary phases in the Th–Fe–Sn system: ThFe0.22Sn2 and Th4Fe13Sn5 have been investigated by high-resolution neutron powder diffraction. The ThFe0.22Sn2 phase crystallizes in an orthorhombic crystal structure, space group Cmcm, whilst Th4Fe13Sn5 crystallizes in the tetragonal space group P4/mbm. In agreement with bulk magnetization measurements, the compound ThFe0.22Sn2 does not order magnetically in the temperature range investigated, while Th4Fe13Sn5 orders below 375 K, with the easy magnetization direction of the Fe moments aligned along the tetragonal c-axis.