Imaging the magnetic nano-domains in Nd2Fe14B

TL;DR

This study uses high-resolution magnetic force microscopy to visualize and analyze nano-scale magnetic domains in Nd2Fe14B single crystals, revealing complex structures and their responses to magnetic fields.

Contribution

It provides detailed imaging of nano-domains in Nd2Fe14B, showing their structure, size, and magnetic field sensitivity, advancing understanding of magnetic microstructure.

Findings

Nano-domains are approximately 20 nm wide.

The star-shaped micrometer domains are composed of nano-domains.

Some nano-domains are sensitive to the MFM tip's magnetic field.

Abstract

We study magnetic domains in Nd2Fe14B single crystals using high resolution magnetic force mi- croscopy (MFM). Previous MFM studies and small angle neutron scattering experiments suggested the presence of nano-scale domains in addition to optically detected micrometer-scale ones. We find, in addition to the elongated, wavy nano-domains reported by a previous MFM study, that the micrometer size, star shape fractal pattern is constructed of an elongated network of nano-domains ~20 nm in width, with resolution-limited domain walls thinner than 2 nm. While the microscopic domains exhibit significant resilience to an external magnetic field, some of the nano-domains are sensitive to the magnetic field of the MFM tip.