Linear and Circularly Polarized Light to Study Anisotropy and Resonant Scattering in Magnetic Thin Films

TL;DR

This paper reviews the polarization properties of synchrotron light and demonstrates how linear and circular polarized X-ray techniques can be used to study magnetic thin films and multilayers, revealing local distortions and magnetic scattering phenomena.

Contribution

It presents new experimental applications of polarized X-ray absorption spectroscopy and magnetic scattering in thin film research at a synchrotron facility.

Findings

Angle-resolved XAS confirms local distortions in strained manganite films.

Grazing incidence X-ray magnetic scattering provides insights into magnetic properties of multilayers.

Polarization techniques enhance the study of magnetic anisotropy and resonant scattering.

Abstract

The remarkable polarization properties of the synchrotron light have lead to the advent of modern synchrotron-related spectroscopic studies with angular and/or magnetic selectivity. We give here an overview of the prominent aspect of the polarization of the light delivered by a bending magnet, and some dichroic properties in X-ray Absorption Spectroscopy (XAS). We report then two studies developed at the Brazilian Synchrotron Light Laboratory (LNLS), exemplifying the profit gained using linear and circular polarization of the X-ray for the study of magnetic thin films and multilayers. Angle-resolved XAS was used in strained manganite thin films to certify a model of local distortion limited within the $MnO_{6}$ polyhedron. A pioneer experience of X-ray magnetic scattering at grazing incidence associated with dispersive XAS in a $Co/Gd$ multilayer draws new perspectives for magnetic studies in thin films and multilayers in atmospheric conditions in the hard X-ray range.