Investigation of interaction mechanisms in nanocomposite PtCo permanent magnetic alloy

The effect of the atomic disorder–order transformation on the interaction mechanisms in isotropic PtCo alloys has been studied by isothermal annealing at 953 K, well below the transformation temperature, for 5–30 min after quenching from 1273 K. The transmission electron microscopy (TEM) testing showed that the ordered regions grew with prolonging heat treatment time. Investigation of the interaction mechanisms in PtCo alloys has been made using analysis of the δM(H) plot. The results of the δM(H) plot and TEM indicate that the interaction mechanisms are changed by the size of the magnetically soft and hard phases. The Kneller–Hawig model was used to explain the continuously changing degree of exchange coupling between the magnetically soft and hard phases.