Structural and magnetoresistance characteristics of CoFe/Ag/NiFe/Ag composite discontinuous multilayers

The structural, magnetic, and giant magnetoresistance (GMR) behaviors of new types of composite multilayers were investigated. The main objective of this study was to accomplish high MR sensitivity while maintaining magnetic softness. The MR sensitivity of CoFe/Ag/NiFe/Ag multilayers was higher compared to CoFe/Ag multilayers mainly due to the switching field difference between NiFe and CoFe. The x-ray diffraction analysis and temperature dependence of Δρ provided evidence of the structural evolution in the CoFe/Ag/NiFe/Ag upon annealing. The temperature dependence of Δρ in CoFe/Ag/NiFe/Ag multilayers annealed for 1 min compared with as-deposited multilayers were reduced because the interface structure was sharpened and structural defects were reduced.