High field neutron diffraction study in Ce(Fe_(0.95)Si_(0.05))_2 compound

摘要

Si substitution at Fe site causes the ferromagnetic to antiferromagnetic (AFM) transition at low temperatures in CeFe_2. We have carried out temperature and field variation of neutron diffraction measurements on Ce(Fe_(0.95)Si_(0.05))_2 to unravel its magnetic structure along with its lattice structure. The Curie temperature (T_c) and the Neel temperature (T_N) are 184 and 82 K, respectively. Above T_N, it exhibits a cubic (Fd3m) structure. On lowering the temperature below T_N, weak superlattice reflections are observed indicating the onset of AFM ordering accompanied by a rhombohedral distortion. The crystal structure in the AFM state is refined in R3m space group.