Domain structure in CoFeB thin films with perpendicular magnetic anisotropy

TL;DR

This paper investigates the domain structures in CoFeB-MgO thin films with perpendicular magnetic anisotropy, analyzing their properties and parameters crucial for device applications using microscopy and magnetometry.

Contribution

It provides a comprehensive analysis of domain wall surface energy, exchange stiffness, and domain wall width in CoFeB thin films with perpendicular magnetic anisotropy.

Findings

Measured domain wall surface energy from stripe domain period

Estimated exchange stiffness and domain wall width

Linked domain parameters to device patterning considerations

Abstract

Domain structures in CoFeB-MgO thin films with a perpendicular easy magnetization axis were observed by magneto-optic Kerr-effect microscopy at various temperatures. The domain wall surface energy was obtained by analyzing the spatial period of the stripe domains and fitting established domain models to the period. In combination with SQUID measurements of magnetization and anisotropy energy, this leads to an estimate of the exchange stiffness and domain wall width in these films. These parameters are essential for determining whether domain walls will form in patterned structures and devices made of such materials.