Electric field effect on the magnetic domain wall creep velocity in Pt/Co/Pd structures with different Co thicknesses

The electric field (EF) modulation of magnetic domain wall (DW) creep velocity v in the Pt/Co/Pd structure with perpendicular magnetic anisotropy (MA) has been studied. The structures with different Co thicknesses tCo up to ∼1 nm are investigated. In all samples, applying a gate voltage induces a clear change in v. Thicker samples provide a higher v modulation efficiency, and the v modulation magnitude of more than a factor of 100 times is observed in the thickest tCo of 0.98 nm. The parameter characterizing the creep motion is significantly affected by the EF, resulting in the modulation of v. Unlike the v case, the MA modulation efficiency decreases with increasing tCo. The present results are discussed based on the EF-induced change in the interfacial Dzyaloshinskii–Moriya interaction (iDMI), which has been recently demonstrated in the same structure, and tCo dependence of the DW energy. The tCo dependence of the v modulation suggests that the EF effect on the iDMI is more important than the MA.The electric field (EF) modulation of magnetic domain wall (DW) creep velocity v in the Pt/Co/Pd structure with perpendicular magnetic anisotropy (MA) has been studied. The structures with different Co thicknesses tCo up to ∼1 nm are investigated. In all samples, applying a gate voltage induces a clear change in v. Thicker samples provide a higher v modulation efficiency, and the v modulation magnitude of more than a factor of 100 times is observed in the thickest tCo of 0.98 nm. The parameter characterizing the creep motion is significantly affected by the EF, resulting in the modulation of v. Unlike the v case, the MA modulation efficiency decreases with increasing tCo. The present results are discussed based on the EF-induced change in the interfacial Dzyaloshinskii–Moriya interaction (iDMI), which has been recently demonstrated in the same structure, and tCo dependence of the DW energy. The tCo dependence of the v modulation suggests that the EF effect on the iDMI is more important than the MA.