부산대학교 도서관

The iron-based oxypnictide superconductor SmFeAsO0.8F0.2 was synthesized under high-pressure and investigated by measuring dc magnetic susceptibility. The zero-field cooled (ZFC) magnetic susceptibility confirmed the bulk superconductivity of the sample with a critical temperature of Tc = 50 K and a significant jump in the magnetization at 4.3 K, usually attributed to the antiferromagnetic ordering of Sm3+ ions in this system. Since the occurrence of the jump depends on the cooling history, our data strongly suggest a spin-glass-like behaviour.