دورية أكاديمية
Oxygen Deficiency and Migration-Mediated Electric Polarization in Magnetic Fe,Co-Substituted SrTiO3−δ
| العنوان: | Oxygen Deficiency and Migration-Mediated Electric Polarization in Magnetic Fe,Co-Substituted SrTiO3−δ |
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| المؤلفون: | Emilio A. Cortés Estay, Shyue P. Ong, Caroline A. Ross, Juan M. Florez |
| المصدر: | Magnetochemistry, Vol 8, Iss 11, p 144 (2022) |
| بيانات النشر: | MDPI AG, 2022. |
| سنة النشر: | 2022 |
| المجموعة: | LCC:Chemistry |
| مصطلحات موضوعية: | multiferroic materials, magnetic perovskites, oxygen vacancy, density functional theory, Chemistry, QD1-999 |
| الوصف: | 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, and give rise to large changes in the electric polarization |ΔP|. We present an intuitive set of rules to describe the properties of STFC, which are based on the interplay between (Co/Fe)-vO defects, magnetic cation coordination, and topological vacancy disorder. STFC structures consist of layered crystals with sheets of linearly organized O4,5,6-coordinated Fe–Co pairs, sandwiched with layers of O5-coordinated Ti. (Co/Fe)-vO defects are the source of crystal distortions, cation off-centering and bending of the oxygen octahedra which, considering the charge redistribution mediated by vO and the cations’ electronegativity and valence states, triggers an effective electric polarization. Oxygen migration for δ=0.125 leads to |ΔP|>∼10 µC/cm2 due to quantum-of-polarization differences between δ=0.125 structures. Increasing the oxygen deficiency to δ=0.25 yields |ΔP|, the O migration of which resolved polarization for δ=0.25 is >∼3 µC/cm2. Magnetism is dominated by the Fe,Co spin states for δ=0.125, and there is a contribution from Ti magnetic moments (∼1 μB) for δ=0.25. Magnetic and electric order parameters change for variations of δ or oxygen migration for a given oxygen deficiency. Our results capture characteristics observed in the end members of the series SrTi(Co,Fe)O3, and suggest the existence of a broader set of rules for oxygen-deficient multiferroic oxides. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2312-7481 11351381 |
| Relation: | https://www.mdpi.com/2312-7481/8/11/144; https://doaj.org/toc/2312-7481 |
| DOI: | 10.3390/magnetochemistry8110144 |
| URL الوصول: | https://doaj.org/article/58c11351381c49e780abe67aad67cbac |
| رقم الأكسشن: | edsdoj.58c11351381c49e780abe67aad67cbac |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 23127481 11351381 |
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| DOI: | 10.3390/magnetochemistry8110144 |