On the electronic structure of the charge-ordered phase in epitaxial and polycrystalline La1-xCaxMnO3 (x = 0.55, 0.67) perovskite manganites

TL;DR

This study investigates the electronic structure of charge-ordered La1-xCaxMnO3 manganites, revealing localized electron states in single-phase samples and clarifying previous anomalies linked to phase separation.

Contribution

It provides experimental evidence supporting localized electronic states in charge-ordered manganites, clarifying the nature of charge transport in these materials.

Findings

Charge transport indicates localized electronic structure.

Delocalized charge anomalies are linked to phase separation.

Experimental techniques include resistivity, magnetoresistance, and admittance spectroscopy.

Abstract

In this work the charge transport properties of charge ordered (CO) La1-xCaxMnO3 (LCMO) (x= 0.55, 0.67) epitaxial thin films and polycrystals are discussed following the recent controversy of localised electron states vs. weakly or de- localised charge density wave (CDW) states in CO manganites. The transport properties were investigated by current vs. voltage, direct current resistivity vs. temperature, local activation energy vs. temperature, magnetoresistance and admittance spectroscopy measurements, which all indicated a localised electronic structure in the single CO phase. Delocalised charge anomalies observed previously may be restricted to phase separated materials.