Oxygen Deficiency and Migration-Mediated Electric Polarization in Magnetic Fe,Co-Substituted SrTiO3−δ
نویسندگان
چکیده
We use density functional theory (DFT) calculations to show that oxygen vacancies (vO) and mobility induce noncentrosymmetric polar structures in SrTi1−x−yFexCoyO3−δ (STFC, x=y=0.125) with δ={0.125,0.25}, enhance the saturation magnetization, give rise large changes electric polarization |ΔP|. present an intuitive set of rules describe properties STFC, which are based on interplay between (Co/Fe)-vO defects, magnetic cation coordination, topological vacancy disorder. STFC consist layered crystals sheets linearly organized O4,5,6-coordinated Fe–Co pairs, sandwiched layers O5-coordinated Ti. defects source crystal distortions, off-centering bending octahedra which, considering charge redistribution mediated by vO cations’ electronegativity valence states, triggers effective polarization. Oxygen migration for δ=0.125 leads |ΔP|>∼10 µC/cm2 due quantum-of-polarization differences structures. Increasing deficiency δ=0.25 yields |ΔP|, O resolved is >∼3 µC/cm2. Magnetism dominated Fe,Co spin states δ=0.125, there a contribution from Ti moments (∼1 μB) δ=0.25. Magnetic order parameters change variations δ or given deficiency. Our results capture characteristics observed end members series SrTi(Co,Fe)O3, suggest existence broader oxygen-deficient multiferroic oxides.
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ژورنال
عنوان ژورنال: Magnetochemistry
سال: 2022
ISSN: ['2312-7481']
DOI: https://doi.org/10.3390/magnetochemistry8110144