Exchange Coupling and Stability of PtMn-Based Spin Valves

The exchange coupling and stability of spin valves with antiferromagnetic (AF) PtMn films were investigated through the correlation between the magnetic properties and their microstructures. The exchange coupling field (Hex) decreases during iterative MR measurements and this decrease associates closely with the changes in the rotational hysteresis loss (Wr), exchange anisotropy energy (Ke) and blocking temperature (Tb) distribution. Ordering of PtMn films that is featured by antiphase configuration is found to play a significant role in determining the exchange coupling properties and stability of these spin valves. Index Terms--Antiferromagnetic Pt-Mn, exchange coupling, magnetoresistance and spin valves, unidirectional anisotropy.