Measuring Lateral Magnetic Structure in Thin Films Using Polarized Neutron Reflectometry

TL;DR

This paper explores how polarized neutron reflectometry can be used to analyze lateral magnetic structures in thin films, including magnetic arrays and domain distributions, through both off-specular and specular reflections.

Contribution

It demonstrates the application of PNR to measure lateral magnetic structures and domain dispersion in thin films, providing new insights into magnetic domain analysis.

Findings

Off-specular reflectivity from micron-sized permalloy arrays observed.

Specular reflection used to study domain dispersion in Co/CoO bilayers.

Preliminary results show potential for detailed magnetic domain characterization.

Abstract

Polarized neutron reflectometry (PNR) has long been applied to measure the magnetic depth profile of thin films. In recent years, interest has increased in observing lateral magnetic structures in a film. While magnetic arrays patterned by lithography and submicron-sized magnetic domains in thin films often give rise to off-specular reflections, micron-sized ferromagnetic domains on a thin film produce few off-specular reflections and the domain distribution information is contained within the specular reflection. In this paper, we will first present some preliminary results of off-specular reflectivity from arrays of micron-sized permalloy rectangular bars. We will then use specular reflections to study the domain dispersion of an exchange-biased Co/CoO bilayer at different locations of the hysteresis loop.