Correlation between crystal planes and disordering of ordered L10 FePt structure caused by ion irradiation

In this study, we investigated the correlation between the crystal planes of L10 FePt and the structure disordering caused by ion irradiation. As part of the experiment, Ar ions were irradiated onto ordered L10 FePt films at several angles, corresponding to different crystal planes. The efficiency of the L10 FePt structure disordering depended on the areal atomic density of the crystal planes facing the ion irradiation direction. Thus, the efficiency of disordering on the (101) crystal plane, which has a lower areal atomic density, was higher than that of the (111) crystal plane, which has a higher areal atomic density. Based on the results of the dose dependence of the L10 structure disordering, the disordered regions seemed to propagate from the surfaces to the bottoms of the films.