Mapping the domain wall pinning landscape in ferromagnetic films

Abstract

The propagation of domain walls in a ferromagnetic film is largely determined by domain wall pinning at defects in the material. In this letter we map the effective potential landscape for domain wall pinning in Permalloy films by raster scanning a single ferromagnetic vortex and monitoring the hysteretic vortex displacement vs. applied magnetic field. The measurement is carried out using a differential magneto-optical microscopy technique which yields spatial sensitivity $\sim 10$ nm. We present a simple algorithm for extracting an effective pinning potential from the measurement of vortex displacement vs. applied field. The resulting maps of the pinning potential reveal distinct types of pinning sites, which we attribute to quasi-zero-, one-, and two-dimensional defects in the Permalloy film.

8 pages, 5 figures

References in corpus (3)

• Dynamics of Pinned Magnetic Vortices
• Effects of Disorder and Internal Dynamics on Vortex Wall Propagation
• Magneto-Optical Imaging of Vortex Domain Deformation in Pinning Sites

Cited by in corpus (4)

• Probing the Pinning Strength of Magnetic Vortex Cores with sub-nm Resolution
• Robust edge states in magnetic domain-wall racetrack
• Relaxation of a single defect spin by the low-frequency gyrotropic mode of a magnetic vortex
• Broadband optomechanical transduction of nanomagnetic spin modes