THE MAGNETIZATION PROCESS AND MAGNETORESISTANCE OF EXCHANGE-SPRING BILAYER SYSTEMS

A perfectly reversible magnetization process was observed in NiFe/CoSm bilayers. During this process, the magnetic moments in the soft magne tic layer (NiFe) are pinned at the interface with the hard magnetic la yer (CoSm), so that the direction of the magnetic moment distributes s uccessively like a Bloch wall. The characteristic reversible magnetiza tion process is explained by an atomic layer model. The magnetoresista nce also exhibits a reversible change reflecting the magnetization pro cess. The basic feature of the reversible magnetoresistance curve is u nderstood to be anisotropic magnetoresistance.