Magnetic domain wall pinning in cobalt ferrite microstructures

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 magnetization vector inside the islands was resolved at the nanoscale, as obtained from magnetic images taken at different x-ray incidence angles. The location of the magnetic domain walls was correlated with the presence of different types of defects as revealed by the different microscopies. This, together with the results of micromagnetic simulations, suggests that the main source of pinning in these microcrystals are linear structural defects induced in the spinel structure by the substrate steps underneath the islands. Our result is of relevance for understanding the different magnetic properties of thin films and nanostructures as compared with the corresponding bulk materials.

Automated summary

This study conducted a detailed analysis of the structural, magnetic, and chemical properties of non-stoichiometric cobalt ferrite micrometric crystals. With the use of advanced techniques such as x-ray magnetic circular dichroism, photoemission microscopy, low-energy electron microscopy, and atomic force microscopy, the magnetization vector inside the crystals was resolved at the nanoscale, and the location of magnetic domain walls was correlated with different types of defects. The findings are crucial for understanding the magnetic properties of thin films and nanostructures.