Particle interactions in the thermal fluctuation aftereffect model of exchange anisotropy

The thermal fluctuation aftereffect model introduced by Fulcomer and Charap (J. Appl. Phys., vol. 42, pp. 4190-4199, October 1972) to explain steady-state hysteresis loops of oxidized magnetic thin films at low temperatures is extended. Interactions among the oxide particles are considered to explain phenomena that depend on magnetic history; e.g., initial contraction of the hysteresis loop and "slow wall motion" in constant applied magnetic field. The model is reduced to a computer calculation of film switching fields for arrays of interacting oxide particles coupled to the film. Reasonable agreement with experimental results is obtained for calculations related to the temperature range near that at which loop displacement first appears.