文章基本信息

标题：Orbital Delocalization and Enhancement of Magnetic Interactions in Perovskite Oxyhydrides
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作者：Kai Liu ; Yusheng Hou ; Xingao Gong 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2016
卷号：6
期号：1
DOI：10.1038/srep19653
语种：English
出版社：Springer Nature
摘要：Recent experiments showed that some perovskite oxyhydrides have surprisingly high magnetic-transition temperature. In order to unveil the origin of this interesting phenomenon, we investigate the magnetism in SrCrO₂H and SrVO₂H on the basis of first-principles calculations and Monte Carlo simulations. Our work indicates that the Cr-O-Cr superexchange interaction in SrCrO₂H is unexpectedly strong. Different from the previous explanation in terms of the H⁻ ion substitution induced increase of the Cr-O-Cr bond angle, we reveal instead that this is mainly because the 3 d orbitals in perovskite oxyhydrides becomes more delocalized since H⁻ ions have weaker electronegativity and less electrons than O²⁻ ions. The delocalized 3 d orbitals result in stronger Cr-O interactions and enhance the magnetic-transition temperature. This novel mechanism is also applicable to the case of SrVO₂H. Furthermore, we predict that SrFeO₂H will have unprecedented high Neel temperature because of the extraordinarily strong Fe-H-Fe σ-type interactions. Our work suggests the anion substitution can be used to effectively manipulate the magnetic properties of perovskite compounds.