Effect of high temperature annealing on ferromagnetism induced by energetic ion irradiation in FeRh alloy

Effects of thermal annealing on ion-irradiation induced ferromagnetism of Fe–50at.%Rh bulk alloy and the related structural change were investigated by means of superconducting quantum interference device (SQUID) and extended X-ray absorption fine structure (EXAFS), respectively. Depending on the annealing temperature from 100 to 500 °C, the magnetization induced by 10 MeV iodine ion irradiation and the lattice structure of the alloy were remarkably changed. After 500 °C annealing, the magnetization and the lattice ordering of the alloy become similar to the states before the irradiation. The experimental result indicates that the thermal relaxation of irradiation-induced atomic disordering dominates the magnetic state of ion-irradiated Fe–50at.% Rh alloy.