Anomalous temperature-dependent magnetization of Ni films on semiconductor substrates

Magnetization, M(T,H=const.) and M(H,T=const.), of Ni films deposited on n-GaAs(1 0 0) and Si(1 0 0) substrates has been performed in magnetic fields both parallel and perpendicular to the film plane. The unsaturated moment of Ni films on n-GaAs substrate around the hysteresis exhibits an anomalous magnetization with temperature in parallel field. In perpendicular field this effect disappears but an undulated hysteresis curve has been observed. Similar Ni films on Si substrate do not exhibit any remarkable anomaly. The effect is likely to originate from the interface of Ni and GaAs