Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Shenyang 110016 , China.
Advanced Institute for Materials Research , Tohoku University , 2-1-1 Katahira , Aoba-ku, Sendai 980-8577 , Japan.
ACS Nano. 2018 Mar 27;12(3):2662-2668. doi: 10.1021/acsnano.7b08802. Epub 2018 Feb 26.
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 FeO twin boundaries (TBs) and determine their concomitant magnetic couplings. We demonstrate that the magnetic coupling across the FeO 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.
阐明材料界面/边界的原子结构如何影响其跨界面的磁耦合性质，具有重要的学术价值，并将有助于先进磁性器件的发展。在这里，我们通过结合原子分辨透射电子显微镜、原子自旋极化第一性原理计算和微分相位衬度成像，对单个 FeO 孪晶界（TB）的原子和电子结构进行了系统的研究，并确定了它们伴随的磁耦合。我们证明，FeO TB 之间的磁耦合可以是反铁磁的或铁磁的，这直接取决于 TB 的原子核心结构和几个原子层内的电子结构。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性行为，这必将促进先进磁性材料和器件的发展。
