Magnetic Aftereffect in Oxidized Ni–Fe Films

Abstract

Displaced hysteresis loops, loop contraction, and increased coercivity are measured in oxidized 76–24 Ni–Fe film at low temperatures at frequencies of 0.05, 20, and 100 Hz using the Kerr effect. Switching in constant applied field by slow wall motion is also observed. A calculation of the observed temperature and frequency dependence of coercivity and loop displacement, based upon the magnetic aftereffect of fine antiferromagnetic oxide particles which are exchange coupled to the ferromagnetic film and have a distribution of anisotropy and coupling energies, is described.