The role of the dopants and oxygen vacancies in the magnetic response of Fe-doped and (Fe, Sn) co-doped SrTiO3 perovskite oxide

Abstract

In this work we present a combined theoreticaland experimental study of the structural, magnetic, and hyperfine properties ofFe doped and (Fe, Sn) co-doped SrTiO3 perovskite (STO). 57Fe-Mössbauer spectroscopy (57Fe-MS) was employed to determine thehyperfine interactions at the Fe sites of doped STO for different Fe and Snconcentrations. The theoretical study was performed in the framework of theDensity Functional Theory (DFT) using the full-potential linearized augmentedplane wave (FP-LAPW) method. The effect of the oxygen vacancies on the magneticand hyperfine properties and on the magnetic alignment of Fe and Sn impuritieswas studied. The combination of the DFT calculations, considering differentstructural models for doped-STO, and 57Fe-MS enable us to obtain a structuralcharacterization of Fe-doped and (Fe, Sn) co-doped STO and to explain the originof the observed hyperfine interactions and the magnetic signal.