Spin-valve thermal stability: The effect of different antiferromagnets

This investigation focused on how spin-valve thermal stability is related to different antiferromagnetic materials: FeMn, IrMn, NiMn, PtMn, and PtPdMn. Measurements of the spin-valve exchange biasing field versus temperature show the following relationship in blocking temperatures: FeMn 250 °C), but are broader. Pinned angle rotation and giant magnetoresistance versus temperature measurements give the same thermal stability hierarchy, as well as providing information about interdiffusion in these spin-valves. For comparison, synthetic antiferromagnet spin-valves (based on IrMn and PtMn) were also measured. The synthetic structures did not show significantly different blocking temperatures or giant magnetoresistance temperature dependence than standard spin-valves. However, blocking temperature distribution and pinned layer rotation measurements showed improved stability for the synthetic structures, which may be attributed to the very thin effective pinned layer which results in high exchange biasing fields in these structures.