Perpendicular giant magnetoresistance of CoFeB/Cu single and dual spin-valve films

Abstract

We present giant magnetoresistance measurements in the current-perpendicular-to-plane mode on single and dual spin valves whose areas are from 0.1 to 1.0 μm2. Dependence on the magnetic layer thickness and the structure was investigated. It was revealed that magnetoresistance change increases 20% by insertion of a nonmagnetic spacer layer in the free layer. The results were analyzed within the framework of the two-current series-resistor model, and proved to be consistent with the theory.