Temperature-dependent changes in structural and magnetic properties of heavy ion irradiated nanoscale Co/Pt multilayers

We report the changes in 100 keV Kr ion-irradiated nanoscale Co/Pt multilayers at different temperatures and fluences.We observe irradiation-induced changes in their structural and magnetic properties. Ion beam-induced mixing across the interfaces leads to the formation of a CoPt ordered/disordered phase. Alarge increase in the coercivity is also observed when the irradiation is performed at room temperature. Such an enhancement in the coercivity is attributed to defect clustering and CoPt ordered/disordered phase formation. The mechanism of phase formation is explained in light of the heat of formation rule.