Behaviors of RKKY Interaction in Ce-based (RE-Gd)Ni Compounds (RE = Ce, Y)

Temperature depedences of magnetization of (Y-Gd)Ni system were investigated in detail to clarify the origin of collapse-like decrease of RKKY interaction observed in (Ce-Gd)Ni at Gd ≤ 20 at%. This collapse-like decrease of RKKY interaction is reflected in the linear variation of magnetization as temperature was increased and the magnetizations of (Y-Gd)Ni system showed no linear behaviors at Gd ≤ 20 at%. Consequently, the collapse-like decrease of RKKY interaction seems to be characteristic of Ce element, whereas the crystal structure of (Y-Gd)Ni system is a little different from that of (Ce-Gd)Ni system. It may be that the Ce disturbs the RKKY interaction between Gd and Gd atoms stemming from 5d and 6s electrons.