Measurements of Nanoscale Domain Wall Flexing in a Ferromagnetic Thin Film

TL;DR

This study combines advanced measurement techniques to investigate the nanoscale elastic flexing of magnetic domain walls in a ferromagnetic thin film, revealing insights into pinning forces and potential for high mobility.

Contribution

It introduces a novel combined measurement approach to analyze nanoscale domain wall flexing and pinning in ferromagnetic thin films.

Findings

Pinning site density estimated at ~10^14 cm^{-3}

Pinning forces around 10 pN identified

Higher intrinsic domain wall mobility suggested

Abstract

We use the high spatial sensitivity of the anomalous Hall effect in the ferromagnetic semiconductor Ga1-xMnxAs, combined with the magneto-optical Kerr effect, to probe the nanoscale elastic flexing behavior of a single magnetic domain wall in a ferromagnetic thin film. Our technique allows position sensitive characterization of the pinning site density, which we estimate to be around 10^14 cm^{-3}. Analysis of single site depinning events and their temperature dependence yields estimates of pinning site forces (10 pN range) as well as the thermal deactivation energy. Finally, our data hints at a much higher intrinsic domain wall mobility for flexing than previously observed in optically-probed micron scale measurements.