Quantitative investigation of FeMn-based spin-valves by rotating field magnetoresistance measurements

Abstract We measure the magnetoresistance of Ta/NiFe/FeMn/NiFe/Co( t Co )/Cu/Co( t Co )/NiFe spin-valves as a function of field strength and direction. The exchange bias H EB and the giant magnetoresistance depend on the Co thickness t Co , and the resistance shows rotational hysteresis when the external field is close to compensating H EB . A single-domain model reproduces the angular dependence of the magnetoresistance in regions without hysteresis, yields H EB values in agreement with MOKE, and allows one to precisely determine the interlayer coupling and uniaxial anisotropies although they are much weaker than H EB .