Spin-valve magnetoresistance of uncoupled Fe-Cu-Co sandwiches

Abstract

The coercive field of thin Co films is strongly dependent on substrate temperature and film thickness, but the magnetic properties of Fe films are only weakly affected by growth conditions. Fe-Cu-Co sandwiches deposited on glass and silicon substrates via electron-beam evaporation exhibit plateaus in their magnetization curves when the coercive field of the Co is made larger than that of the Fe. These plateaus correspond to an applied field region in which the Co and Fe moments are antialigned and the resistance is enhanced. The isotropic or spin-valve part of the magnetoresistance is as large as 3.3% in some sandwiches. The spin-valve magnetoresistance has a broad peak centered at a ferromagnetic layer thickness of 60 Å.