Electronic inhomogeneity in EuO: Possibility of magnetic polaron states

TL;DR

This study uses infrared magneto-optical imaging to reveal electronic inhomogeneity in EuO thin films, suggesting magnetic polaron states as a possible origin of the observed inhomogeneity near the ferromagnetic transition.

Contribution

It provides direct spatial imaging evidence of electronic inhomogeneity and proposes magnetic polarons as a potential explanation in EuO.

Findings

Spatial inhomogeneity observed in EuO thin films.

Transition from paramagnetic to ferromagnetic state involves inhomogeneous phases.

Magnetic polaron states may explain the inhomogeneity.

Abstract

We have observed the spatial inhomogeneity of the electronic structure of a single-crystalline electron-doped EuO thin film with ferromagnetic ordering by employing infrared magneto-optical imaging with synchrotron radiation. The uniform paramagnetic electronic structure changes to a uniform ferromagnetic structure via an inhomogeneous state with decreasing temperature and increasing magnetic field slightly above the ordering temperature. One possibility of the origin of the inhomogeneity is the appearance of magnetic polaron states.