Tailoring of Domain Wall Devices for Sensing Applications

We perform magnetoresistance (MR) measurements to experimentally track magnetic domain wall pinning/depinning process in L-shaped Permalloy (Py) nanostructures with widths in the range 50-400 nm. We demonstrate that the field interval between the pinning/depinning events increases with the reduction of the nanowire width. The most reproducible measurements are obtained from the narrowest devices. MR measurements reveal that the stochastic contribution to pinning/depinning processes is higher when the applied field is oriented symmetrically with respect to both arms of the device. The interpretation of experimental results is supported by micromagnetic simulations.