Quantitative determination of vortex core dimensions in head‑to‑head domain walls using off‑axis electron holography

In this paper, we present a complete three-dimensional characterization of vortex core spin structures, which is important for future magnetic data storage based on vortex cores in disks and in wires. Using electron holography to examine vortices in patterned Permalloy devices we have quantitatively measured the in-plane and out-of-plane magnetization of a vortex core.

Observed core widths and integrated phase shifts agree well with those derived from micromagnetic simulations.