Effect of direct exchange coupling between antiferromagnetic grains on magnetic behavior of ferro/antiferromagnetic exchange coupled polycrystalline layer systems

Two fundamental properties, unidirectional rotational hysteresis and traini ng effect, of ferro/antiferromagnetic exchange coupled polycrystalline laye r systems are discussed in which a direct exchange coupling between antifer romagnetic grains is found to play a decisive role. A new model is proposed to describe the systems. The analysis of some experimental data suggests t he existence of preferential angular distribution of anisotropy axes of ant iferromagnetic grains. (C) 2001 Elsevier Science B.V. All rights reserved.