揭示纳米晶镍中缺陷诱导的自旋无序
介观与纳米尺度物理
2021-04-23 v4
摘要
我们结合磁强计与磁性小角中子散射，研究微观结构对通过高压扭转应变制备的纳米晶镍块体样品宏观磁性的影响。如磁强计所见，与非变形多晶镍相比，机械变形导致矫顽力显著增加。中子数据揭示了由样品内高密度晶体缺陷引起的显著自旋错位散射，这些缺陷由制备过程中的剧烈塑性变形产生。表征实空间中磁化涨落特征的相应磁关联长度指示出平均缺陷尺寸为 11 nm，小于 60 nm 的平均晶粒尺寸。在剩磁态下，缺陷周围的应变场在周围铁磁体内引起自旋无序，其穿透深度约为 22 nm。该无序的范围与幅度随外磁场增大而被系统性抑制。我们的发现得到微磁仿真的支持与阐明，针对嵌入铁磁镍相中的非磁性缺陷（孔洞）这一特例，进一步凸显了局域自旋扰动对富缺陷磁体（如高压扭转材料）磁微结构的作用。
引用
@article{arxiv.2011.11318,
title = {Revealing defect-induced spin disorder in nanocrystalline Ni},
author = {Mathias Bersweiler and Evelyn Pratami Sinaga and Inma Peral and Nozomu Adachi and Philipp Bender and Nina-Juliane Steinke and Elliot Paul Gilbert and Yoshikazu Todaka and Andreas Michels and Yojiro Oba},
journal= {arXiv preprint arXiv:2011.11318},
year = {2021}
}
备注
This is the version of the article accepted for publication in Physical Review Materials including all changes made as a result of the peer review process, and which may also include the addition to the article by APS of a header, an article ID, a cover sheet and/or an Accepted Manuscript watermark, but excluding any other editing, typesetting or other changes made by APS and/or its licensors