Murakami Y, Niitsu K, Tanigaki T, Kainuma R, Park H S, Shindo D
1] Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan [2] Center for Emergent Matter Science, RIKEN, Wako 351-0198, Japan.
1] Center for Emergent Matter Science, RIKEN, Wako 351-0198, Japan [2] Department of Materials Science, Tohoku University, Sendai 980-8579, Japan.
Nat Commun. 2014 Jun 18;5:4133. doi: 10.1038/ncomms5133.
Direct magnetization measurements from narrow, complex-shaped antiphase boundaries (APBs; that is, planar defect produced in any ordered crystals) are vitally important for advances in materials science and engineering. However, in-depth examination of APBs has been hampered by the lack of experimental tools. Here, based on electron microscopy observations, we report the unusual relationship between APBs and ferromagnetic spin order in Fe70Al30. Thermally induced APBs show a finite width (2-3 nm), within which significant atomic disordering occurs. Electron holography studies revealed an unexpectedly large magnetic flux density at the APBs, amplified by approximately 60% (at 293 K) compared with the matrix value. At elevated temperatures, the specimens showed a peculiar spin texture wherein the ferromagnetic phase was confined within the APB region. These observations demonstrate ferromagnetism stabilized by structural disorder within APBs, which is in direct contrast to the traditional understanding. The results accordingly provide rich conceptual insights for engineering APB-induced phenomena.
对狭窄、形状复杂的反相畴界（APB，即在任何有序晶体中产生的平面缺陷）进行直接磁化测量对于材料科学与工程的进展至关重要。然而，由于缺乏实验工具，对APB的深入研究受到了阻碍。在此，基于电子显微镜观察，我们报告了Fe70Al30中APB与铁磁自旋序之间的异常关系。热诱导的APB具有有限的宽度（2 - 3纳米），在该宽度范围内会发生显著的原子无序。电子全息研究表明，APB处的磁通密度出人意料地大，与基体值相比，在293K时放大了约60%。在高温下，试样呈现出一种奇特的自旋织构，其中铁磁相局限于APB区域内。这些观察结果表明，APB内的结构无序稳定了铁磁性，这与传统认识形成了直接对比。因此，这些结果为设计APB诱导现象提供了丰富的概念性见解。
