Crystal Growth, Structural Transition, and Magnetic Properties of Ho 5 Pd 4 Sn 12 .

Single crystals and polycrystalline samples of Ho 5 Pd 4 Sn 12 have been synthesized using flux and arc-melting methods, respectively. Single-crystal X-ray diffraction studies indicate that Ho 5 Pd 4 Sn 12 crystallizes in a tetragonal structure ( I 4/ m ) at room temperature and transforms into a monoclinic structure ( C 2/ m ) below ∼194 K. This structural transition is further supported by a transmission electron microscopy study and an anomaly at ∼194 K in the specific heat data. Temperature-dependent resistivity data also show a kink around the structural transition temperature. Ho 5 Pd 4 Sn 12 is antiferromagnetically ordered below 7 K. Ho 5 Pd 4 Sn 12 shows magnetic anisotropy, and the isothermal magnetization curve ( H ⊥ c ) at 2 K exhibits a field-induced magnetic phase transition around 22.8 kOe.