We investigated magnetic textures in a Sc-doped hexaferrite film by means of phase microscopy (PM) with a hole-free phase plate in a transmission electron microscope. In a zero magnetic field, the stripe-shaped magnetic domains coexist with magnetic bubbles. The magnetization in both magnetic domains was oriented perpendicular to the film and the domain walls have an in-plane magnetization. In the remnant state at 9.2 mT, several magnetic bubbles were formed with the formation of stripe-shaped magnetic domains, and the out-of-plane component in the stripe-shaped domains gradually appeared as the film thickness increased. As the film thickness increases further, the magnetic bubbles with clockwise or counter-clockwise spin helicities formed a triangular lattice. These results in the remnant state suggest that the domain wall energy in the magnetic bubble domains is lower in the thicker region.
@article{arxiv.2105.00396,
title = {Magnetic textures in a hexaferrite thin film and their response to magnetic fields revealed by phase microscopy},
author = {Atsuhiro Kotani and Ken Harada and Marek Malac and Hiroshi Nakajima and Kosuke Kurushima and Shigeo Mori},
journal= {arXiv preprint arXiv:2105.00396},
year = {2021}
}