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arXiv · 1907.05961

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

Mariel A. Opazo·Shyue Ping Ong·P. Vargas·C. A. Ross·Juan M. Florez
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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$_{3-δ}$ with x = y = 0.125 and $δ$ = (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 $δ$ = 0.125. This qualitatively mimics the previously reported magnetization measured for SrTiFeO$_{3-δ}$, which was maximum at an intermediate deposition pressure of oxygen.

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Mariel A. Opazo, Shyue Ping Ong, P. Vargas, C. A. Ross, Juan M. Florez. 2019-07-12. Oxygen-vacancy tuning of magnetism in SrTi$_{0.75}$Fe$_{0.125}$Co$_{0.125}$O$_{3-δ}$ perovskite. https://doi.org/10.1103/physrevmaterials.3.014404

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