Measurement of magnetization using domain compressibility in CoFeB films with perpendicular anisotropy

TL;DR

This paper introduces a novel method to measure the saturation magnetization of ultrathin CoFeB films with perpendicular anisotropy by analyzing domain wall interactions, providing insights into magnetic properties and storage limits.

Contribution

The study presents a new technique based on domain compressibility to map magnetization in ultrathin films, advancing magnetic characterization methods.

Findings

The method accurately maps saturation magnetization of CoFeB films.

It determines the minimal domain wall distance before merging.

Provides practical limits for spintronic storage density.

Abstract

We present a method to map the saturation magnetization of soft ultrathin films with perpendicular anisotropy, and we illustrate it to assess the compositional dependence of the magnetization of CoFeB(1 nm)/MgO films. The method relies on the measurement of the dipolar repulsion of parallel domain walls that define a linear domain. The film magnetization is linked to the field compressibility of the domain. The method also yields the minimal distance between two walls before their merging, which sets a practical limit to the storage density in spintronic devices using domain walls as storage entities.