Hydrogen-induced modulation of magnetic domain wall creep velocity in Pd/Co/Pd system

The magnetic properties of Pd/ferromagnet multilayers can be controlled by hydrogen absorption in Pd, which exhibits an excellent hydrogen absorption capability. Although various magnetic properties have been modulated using this method, its effect on magnetic domain wall (DW) dynamics remains incompletely understood. In this study, we investigated the hydrogen-induced modulation of thermally activated DW creep velocity in a perpendicularly magnetized Pd/Co/Pd structure. Hydrogen absorption in Pd was conducted by exposing the sample to hydrogen gas. We found that hydrogen absorption enhanced effective DW pinning strength, resulting in a decrease in velocity. The velocity recovered to its initial value after hydrogen desorption. Analysis of the hydrogen effect on DW energy suggests that the velocity reduction cannot be explained solely by the modulation of magnetic anisotropy; instead, changes in the DW pinning landscape and/or interfacial Dzyaloshinskii–Moriya interaction are likely involved. Our findings provide crucial insights for the development of hydrogen-based spintronics devices.