Magnetic domain wall pinning in cobalt ferrite microstructures

TL;DR

This study combines advanced microscopy and magnetic imaging techniques to analyze how structural defects in cobalt ferrite microstructures influence magnetic domain wall pinning, revealing substrate-induced defects as primary pinning sites.

Contribution

It introduces a comprehensive correlative analysis linking structural defects to magnetic domain wall pinning in cobalt ferrite microstructures, highlighting the role of substrate steps.

Findings

Linear structural defects are the main pinning sites.

Magnetic domain walls are pinned by substrate-induced defects.

Correlative microscopy effectively identifies defect-related pinning mechanisms.

Abstract

A detailed correlative structural, magnetic and chemical analysis of non-stoichiometric cobalt ferrite micrometric crystals was performed by x-ray magnetic circular dichroism combined with photoemission microscopy, low energy electron microscopy, and atomic force microscopy. The vector magnetization at the nanoscale is obtained from magnetic images at different x-ray incidence angles and compared with micromagnetic simulations, revealing the presence of defects which pin the magnetic domain walls. A comparison of different types of defects and the domain walls location suggests that the main source of pinning in these microcrystals are linear structural defects induced in the spinel by the substrate steps underneath the islands.