Magnetoresistance and morphology in magnetic multilayers by insertion of very thin Fe, Co layers

Dependences of magnetoresistance and morphology upon the insertion of very thin magnetic layers at interfaces between magnetic and nonmagnetic layers in Co/Cu and Ni81Fe19/Cu multilayers have been investigated. The Co/Cu multilayers with inserted Fe thickness of 0.5 similar to 1.0 Angstrom have the MR ratio of about 18% more than the noninserted multilayers, and the MR ratio in the NiFe/Cu multilayers with inserted Co of thickness of 3 Angstrom was found to be significantly increased. These results can be explained by the enhanced interlayer antiferromagnetic coupling and spin-dependent scattering phenomena at the interface. Of particular interest, the ''Clustered out-growth'' in the surface morphology of these multilayers was observed.