  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.
