Effect of strain on the electronic structure of La0.7Ca0.3MnO3

TL;DR

This study investigates how substrate-induced strain affects the electronic valence band structure of La0.7Ca0.3MnO3 thin films, revealing significant alterations linked to orbital occupancy and crystal field changes.

Contribution

It provides experimental evidence of strain's impact on the electronic structure of La0.7Ca0.3MnO3, using synchrotron x-ray spectroscopy and detailed analysis.

Findings

Strain significantly alters the valence band structure.

Orbital occupancy and crystal field splitting are affected by strain.

Electronic structure changes are linked to Mn-O bond length variations.

Abstract

The effect of substrate strain on the electronic valence band structure of La0.7Ca0.3MnO3 thin films has been investigated. For this purpose La0.7Ca0.3MnO3 thin films have been simultaneously grown on SrTiO3 and LaAlO3 substrates using pulsed laser deposition technique. These samples were characterized by x-ray diffraction, x-ray reflectivity, core level x-ray photoelectron spectroscopy, and scanning electron microscopy measurements. Our experiments confirmed that all these samples have same chemical composition but different strain configuration. The electronic structure of these samples is probed through valence band spectroscopy measurements on Indus-1 synchrotron x-ray source. We observe that strain has large effect on the valence band electronic structure of La0.7Ca0.3MnO3. The results are explained on the basis of strain induced orbital occupancy and change in the crystal field splitting due to Mn-O bond length.