Magnetic bubbles in an M-type hexagonal ferrite observed by hollow-cone Foucault imaging and small-angle electron diffraction

TL;DR

This study employs hollow-cone Foucault imaging and small-angle electron diffraction to visualize and analyze nanoscale magnetic textures, such as magnetic-striped domains and bubbles, in a specific hexagonal ferrite material, revealing in-plane magnetization directions.

Contribution

It demonstrates the effectiveness of hollow-cone Foucault imaging combined with electron diffraction for visualizing magnetic textures and determining magnetization directions in nanoscale domains.

Findings

Magnetic domains with various magnetization directions can be visualized in focus.

Contrast of domain walls depends on illumination angle.

Magnetization at domain walls is in-plane in both striped domains and bubbles.

Abstract

We report hollow-cone imaging and small-angle electron diffraction of nanoscale magnetic textures such as magnetic-striped domains and magnetic bubbles of M-type hexagonal ferrite BaFe$_{10.35}$Sc$_{1.6}$Mg$_{0.05}$O$_{19}$. The advantage of the hollow-cone Foucault method is that magnetic domains with various directions of magnetization can be visualized under an infocus condition. Moreover, the contrast of magnetic domain walls in magnetic bubbles depends on the inclination angle of the illumination beam. The combination of small-angle electron diffraction and hollow-cone Foucault imaging proves that magnetization at domain walls exhibits in-plane directions in the magnetic-striped domains and magnetic bubbles.