Fe-resonant valence band photoemission and oxygen NEXAFS study on La1-xSrxFe0.75Ni0.25O3-{\delta}

TL;DR

This study investigates how Sr and Ni substitutions in LaFeO3 affect the electronic structure and conductivity, revealing hole formation and changes in valence band features through resonant photoemission and NEXAFS techniques.

Contribution

It provides new insights into the electronic structure modifications due to Sr and Ni doping in LaFeO3 using resonant photoemission and NEXAFS analysis.

Findings

Ni substitution creates electron holes mainly of O 2p character.

Sr substitution increases hole concentration, suppressing eg structure.

Changes in electronic structure correlate with electrical conductivity variations.

Abstract

Iron resonant valance band photoemission spectra of Sr substituted LaFe0.75Ni0.25 O3-{\delta} have been recorded across the Fe 2p - 3d absorption threshold to obtain Fe specific spectral information on the 3d projected partial density of states. Comparison with La1-xSrxFeO3 resonant VB PES literature data suggests that substitution of Fe by Ni forms electron holes which are mainly O 2p character. Substitution of La by Sr increases the hole concentration to an extent that the eg structure vanishes. The variation of the eg and t2g structures is paralleled by the changes in the electrical conductivity.