# Oxygen-vacancy tuning of magnetism in SrTi$_{0.75}$Fe$_{0.125}$Co$_{0.125}$O$_{3-\delta}$ perovskite

## TL;DR

This study employs density functional theory to explore how oxygen vacancies influence the structure, electronic properties, and magnetism of a specific doped perovskite, revealing that oxygen deficiency modulates valence states, magnetization, and band-gap.

## Contribution

It provides a detailed theoretical analysis of oxygen vacancy effects on magnetic and electronic properties in SrTiFeCoO3-elta, highlighting the role of vacancy location and spin states.

## Key findings

- Magnetization peaks at elta=0.125
- Valence and spin states depend on oxygen vacancies
- Band gap varies with oxygen deficiency

## Abstract

We use density functional theory to calculate the structure, band-gap and magnetic properties of oxygen-deficient SrTi$_{1-x-y}$Fe$_x$Co$_y$O$_{3-\delta}$ with x = y = 0.125 and ${\delta}$ = (0,0.125,0.25). The valence and the high or low spin-states of the Co and Fe ions, as well as the lattice distortion and the band-gap, depend on the oxygen deficiency, the locations of the vacancies, and on the direction of the Fe-Co axis. A charge redistribution that resembles a self-regulatory response lies behind the valence spin-state changes. Ferromagnetism dominates, and both the magnetization and the band gap are greatest at ${\delta}$ = 0.125. This qualitatively mimics the previously reported magnetization measured for SrTiFeO$_{3-\delta}$, which was maximum at an intermediate deposition pressure of oxygen.