Hysteresis properties and interlayer binding in film sandwiches

A study is made into reversal magnetization for Fe15Co20Ni65/Fe15Co20Ni65 sandwich films with crossed easiest magnetization axes and for Fe15Co20NLi65/Cu/Fe15Co20Ni65 sandwiches with layers of different coercive force. The dependences of magnetic anisotropy, magnetic hysteresis and magnetoresistance on the thickness of nonmagnetic interlayers (L) are determined. Based on their analysis three levels of magnetic interlayer coupling are revealed which correspond to three L ranges. Possible mechanisms of interlayer coupling are pointed out. It is revealed that the layer-by-layer reversal magnetization needed for the origination of spin-valve magnetoresistive effect is realized at L exceeding 2