Spin Glass-like Anomalous Memory in Ferromagnetic MCl2-GIC3 (M: Co, Ni)

Memory phenomena in the ordered state of triangular ferromagnets CoCl2- and NiCl2 graphite intercalation compounds (GIC) are investigated by the measurement of thermoremanent and field induced magnetizations. The results are compared with the theoretically expected one for spin glass. Measurement for a typical spin glass CuMn alloy is undertaken for a comparison. An anomalous memory is revealed in the intermediate state, which shows apparently characteristics of both ordered and disordered states.