Subtractively Prepared Permalloy Nanowires for Spin-Torque Experiments

Physical properties of Permalloy (Ni₈₀Fe₂₀) can be considerably enhanced by sputtering on substrates heated to temperatures around 300 °C. To enable the use of sputtered Permalloy in micro- and nanostructures for spintronic experiments a subtractive preparation process has to be established, as common lift-off processing is incompatible with high temperatures. Two subtractive fabrication processes for curved Permalloy nanowires are executed: Ion-milling and rf-sputter-etching. The results of current-induced domain-wall depinning experiments with these nanowires are compared.