Direct Determination of Atomic Structure and Magnetic Coupling of Magnetite Twin Boundaries
Direct Determination of Atomic Structure and Magnetic Coupling of Magnetite Twin Boundaries
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磁铁矿孪晶界原子结构和磁耦合的直接测定
DOI：
10.1021/acsnano.7b08802
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发表时间：
2018-03-01
期刊：
影响因子：
17.1
通讯作者：
Ikuhara, Yuichi
中科院分区：
文献类型：
--
作者：
Chen, Chunlin;Li, Hongping;Ikuhara, Yuichi
阐明材料中界面/边界的原子结构如何影响它们之间的磁耦合性质具有重要的学术价值，并将促进最先进的磁性器件的开发。在这里，通过结合原子分辨率透射电子显微镜、原子自旋偏振第一原理计算和微分相衬成像，我们对单个 Fe3O4 孪晶界 (TB) 的原子和电子结构进行了系统研究，并确定了它们伴随的磁耦合。我们证明，Fe3O4 TB 上的磁耦合可以是反铁磁的，也可以是铁磁的，这直接取决于 TB 原子核心结构和几个原子层内的最终电子结构。揭示局部原子结构与单个晶界磁性能之间的一一对应关系将有助于深入理解广泛使用的多晶磁性材料的许多有趣的磁行为，这必将促进先进磁性材料和器件的发展。
Clarifying how the atomic structure of interfaces/boundaries in materials affects the magnetic coupling nature across them is of significant academic value and will facilitate the development of state-of-the-art magnetic devices. Here, by combining atomic-resolution transmission electron microscopy, atomistic spin polarized first-principles calculations, and differential phase contrast imaging, we conduct a systematic investigation of the atomic and electronic structures of individual Fe3O4 twin boundaries (TBs) and determine their concomitant magnetic couplings. We demonstrate that the magnetic coupling across the Fe3O4 TBs can be either antiferromagnetic or ferromagnetic, which directly depends on the TB atomic core structures and resultant electronic structures within a few atomic layers. Revealing the one-to-one correspondence between local atomic structures and magnetic properties of individual grain boundaries will shed light on in-depth understanding of many interesting magnetic behaviors of widely used polycrystalline magnetic materials, which will surely promote the development of advanced magnetic materials and devices.