Spin-valve thermal stability: Interdiffusion versus exchange biasing

This paper focuses on the roles of exchange biasing and interdiffusion on t he thermal stability of different spin-valve structures. The thermal stabil ity of the exchange field was found to be an intrinsic property of the anti ferromanget structure-it is not significantly effected by roughness or the quality of crystalline texture in the spin-valve. Two routes for interdiffu sion were observed: mixing at the Ta/NiFe interface and Mn interdiffusion i nto the pinned layer and beyond. Synthetic spin-valves showed improved ther mal stability as the Ru layer acts as a barrier against Mn interdiffusion, Annealing the PtMn spin-valves significantly reduced interdiffusion, induci ng a phase transition to the more stable PtMn fct state and passivating the Ta/NiFe intermixing.