Magnetic transition in the rare earth intermetallic compound Ce_5Ge_4: Heat capacity and neutron diffraction studies

摘要

Polycrystalline Ce_5Ge_4 compound (orfhorhombic Sm_5Ge_4-type structure, space group Prima, No. 62) orders ferromagnetically at ～12 K (T_C). Low field dc magnetization and ac magnetic susceptibility data reveal presence of competing magnetic interactions below T_C. Heat capacity of Ce_5Ge_4 in zero applied field indicates a second order transition with a peak centered at 11 K. Powder neutron diffraction studies confirm the existence of a commensurate magnetic order in this compound at 10 K without a change of crystal structure. The Ce moments lie in the ab plane and the moment at Ce site is found to be only ～0.4 μ_B at this temperature.