Asymmetric reversal in aged high concentration CuMn alloy.

The magnetic hysteresis loops of an aged Cu(81.2)Mn(18.8) alloy sample exhibit significant asymmetric reversal at low temperatures, with high sensitivity to the cooling field. Much of the observed behaviour was explained by considering an ensemble of coherent, ferromagnetically aligned clusters interacting with a randomized spin glass component. A modified Stoner-Wohlfarth model was successfully applied to the data using Monte Carlo simulations, in order to gain insight into the dependence of the cluster shape anisotropy and exchange anisotropy on the cooling field. This model suggested that ferromagnetic clusters grow as the cooling field increases.