CHANGES IN MAGNETIC AND MAGNETORESISTIVE PROPERTIES OF NIFE AG MULTILAYERS INDUCED BY THERMAL ANNEAL/

Permalloy/silver (NiFe/Ag) multilayers, consisting of ten similar to 5 .0 nm and similar to 2.5 nm thick layers, respectively, were annealed in the 553-693 K interval. Magnetization, resistivity and magnetoresis tance of the annealed samples were measured to test their relationship with the structural changes occurring in the multilayer The results s upport the previously reported conclusions, namely that during low tem perature annealing (up to 633 K) Ag diffusion occurs along the boundar ies of the columnar grains, resulting in formation of individual NiFe grains within former permalloy layers. At higher temperature annealing relatively large Ag and NiFe agglomerates grow and break up the multi layered structure. It was shown, that at room temperature the coercive field and magnetoresistance are the most structural sensitive, while the changes in resistivity are masked by phonon scattering contributio n.