Consequences of the CMR effect on EELS in TEM

TL;DR

This paper investigates how the colossal magnetoresistance (CMR) effect in double perovskite oxides influences EELS signals, revealing changes in band gap and enabling magnetisation studies via EMCD below the Curie temperature.

Contribution

It demonstrates the impact of the CMR effect on EELS measurements and introduces a method to study magnetisation with chemical sensitivity using EMCD in La2CoMnO6 thin films.

Findings

Change in band gap at low energy losses due to CMR effect

Ability to study magnetisation with chemical sensitivity using EMCD

EELS signals are affected by the CMR effect in double perovskite oxides

Abstract

Double perovskite oxides have gained in importance and exhibit negative magnetoresistance, which is known as colossal magnetoresistance (CMR) effect. Using a La$_2$CoMnO$_6$ (LCM) thin film we prove that the physical consequences of the CMR effect do also influence the electron energy loss spectrometry (EELS) signal. We observe a change of the band gap at low energy losses and are able to study the magnetisation with chemical sensitivity by employing energy loss magnetic chiral dichroism (EMCD) below the Curie temperature T$_C$ where the CMR effect becomes significant.