A microspectroscopic study of the electronic homogeneity of ordered and disordered Sr2FeMoO6

TL;DR

This study uses microspectroscopy to reveal that electronic and magnetic inhomogeneities in disordered Sr2FeMoO6 are caused by chemical composition fluctuations, affecting magnetic properties.

Contribution

It provides direct spatially resolved evidence linking electronic inhomogeneity to chemical disorder in Sr2FeMoO6, clarifying the origin of magnetic variability.

Findings

Disordered samples show significant electronic inhomogeneity.

Chemical inhomogeneity correlates with Fe-rich and Mo-rich regions.

Electronic inhomogeneity impacts magnetic behavior.

Abstract

Besides a drastic reduction in saturation magnetization of disordered Sr2FeMoO6 compared to highly ordered samples, magnetizations as a function of the temperature for different disordered samples may also show qualitatively different behaviors. We investigate the origin of such diversity by performing spatially resolved photoemission spectroscopy on various disordered samples. Our results establish that extensive electronic inhomogeneity, arising most probably from an underlying chemical inhomogeneity in disordered samples is responsible for the observed magnetic inhomogeneity. It is further pointed out that these inhomogeneities are connected with composition fluctuations of the type Sr2Fe1+xMo1-xO6 with Fe-rich (x>0) and Mo-rich (x<0) regions.