Lorentz microscopy mapping for domain walls structure study in L1$_0$ FePd thin films

TL;DR

This study uses Lorentz Transmission Electron Microscopy to analyze the structure of domain walls in L1$_0$ FePd thin films, demonstrating a new method for magnetic characterization of perpendicular anisotropy materials.

Contribution

The paper introduces an original approach for quantitative magnetic induction measurements and confirms the effectiveness of LTEM in studying domain wall configurations in FePd alloys.

Findings

Successful mapping of domain wall structures in FePd thin films

Validation of LTEM as a precise tool for magnetic characterization

Observation of irregularities along domain walls that influence magnetization

Abstract

Thin film alloys with perpendicular anisotropy were studied using Lorentz Transmission Electron Microscopy (LTEM). This work focuses on the configuration of domain walls and demonstrates the suitability and accuracy of LTEM for the magnetic characterisation of perpendicular magnetic anisotropy materials. Thin films of chemically ordered ($\unit{L1_0}$) FePd alloys were investigated by micro-magnetic modelling and LTEM phase retrieval approach. The different components of magnetization described by the modeling were studied on experimental images and confirmed by LTEM contrast simulation. Furthermore, quantitative measurements of magnetic induction inside the domain walls were made by using an original method to separate the electrical and magnetical contributions to the phase information. Irregularities were also observed along the domain walls which could play a major role during the magnetization processes.