Current-induced domain-wall motion in patterned nanowires with various Gd–Fe compositions for magneto-optical light modulator applications

We have fabricated nanowires with various compositions of Gd x –Fe1− x and evaluated current-induced domain-wall (DW) motion for magneto-optical light modulator application. Successful DW expansion and shrinkage according to the direction of current injection using two nanomagnets aligned in an anti-parallel configuration. The fastest DW velocity was obtained with Gd22.7Fe77.3, which is slightly Fe richer than the magnetization compensation composition. This composition that gave the highest DW velocity was attributed to the angular momentum compensation composition in Gd–Fe, which is slightly Fe richer than the compensation composition.