Soft X-ray Absorption Spectroscopy Study of Multiferroic Bi-substituted Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3)

TL;DR

This study investigates the electronic structures of Bi-substituted BaTiFeO3 multiferroic oxides using soft X-ray absorption spectroscopy, revealing valence state changes of Fe ions with Bi substitution and their implications for electronic and magnetic properties.

Contribution

It provides detailed insights into the valence states of Fe and Ti ions in Bi-substituted BaTiFeO3, highlighting how Bi substitution affects electronic structure and magnetic behavior.

Findings

Fe ions are Fe2+-Fe3+ mixed-valent for x > 0

Ti ions remain in Ti4+ state across all x

Fe valence decreases from ~3 to ~2.6 with increasing x

Abstract

The electronic structures of multiferroic oxides of Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3) (0 < x < 0.12) have been investigated by employing photoemission spectroscopy and soft x-ray absorption spectroscopy (XAS). The measured Fe and Ti 2p XAS spectra show that Ti ions are in the Ti4+ states for all x and that Fe ions are Fe2+-Fe3+ mixed-valent for x > 0. The valence states of Fe ions are found to be nearly trivalent for x=0, and decreases with increasing x from being nearly trivalent (v(Fe)~ 3) for x=0 to v(Fe)~ 2.6 for x=0.12. The valence states of both Ti and Ba ions do not change for all x < 0.12. Based on the obtained valence states of Fe ions, the electronic and magnetic properties of Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3) are explored.