文章信息/Info

Title:

Magnetic Domain Imaging by Differential Phase Contrast Technique of Transmission Electronic Microscopy

文章編號:

1674-3962(2021)11-0851-10

作者:

湯進1; 吳耀東1; 2; 熊奕敏1; 田明亮1; 杜海峰1

（1. 中國科學院合肥物質科學研究院 強磁場科學中心 極端條件凝聚態物理安徽省重點實驗室，安徽 合肥 230031）（2. 合肥師范學院物理與材料工程學院，安徽 合肥 230061）

Author(s):

TANG Jin1;  WU Yaodong1; 2;  XIONG Yimin1;  TIAN Mingliang1;  DU Haifeng1

（1. Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China）（2. School of Physics and Materials Engineering, Hefei Normal University, Hefei 230061, China）

關鍵詞:

透射電子顯微鏡; 差分相位分析; 磁疇; 斯格明子�泊排�; 中心對稱磁體

Keywords:

transmission electronic microscopy;  differential phase contrast;  magnetic domain;  Skyrmion�瞓ubble;  centrosymmetric uniaxial magnet

分類號:

TH742

DOI:

10.7502/j.issn.1674-3962.202107019

文獻標志碼:

A

摘要:

透射電子顯微鏡具有高空間磁分辨率和易集成的多場調控等特點，成為當下納米尺度下先進磁結構觀測的主要手段之一。首先介紹和比較了透射電鏡磁表征的3種模式：洛倫茨模式、電子全息模式和差分相位分析模式，然后詳細綜述了差分相位分析技術表征一類中心對稱晶體Fe3Sn2材料中新型磁疇結構的研究進展。在該研究中，首先結合差分相位分析技術和三維微磁學模擬，闡釋了中心對稱材料中復雜“多拓撲態”磁疇起源于磁結構的三維特性，隨后基于該材料溫度誘導自旋重取向內稟物性，在Fe3Sn2受限納米盤中，利用差分相位分析技術發現了一類全新的渦旋狀磁結構“靶磁泡”，研究了其磁場演化行為，最后提出了斯格明子�泊排莼�存儲器的概念，并實現了磁場和電流高度可控斯格明子�泊排萃負浯呸D變。差分相位分析技術揭示的中心對稱磁性材料納米結構中的新穎磁疇及豐富的電流驅動動力學，有望促進未來基于新型磁疇結構的拓撲相關自旋電子學器件的開發。

Abstract:

Transmission electronic microscopy (TEM) has become one of the most advanced techniques to observe nanometric-sized magnetic domains, owing to its high spatial magnetic resolution and easy accessibility in integrating multiple physic fields. Here, we compared three techniques of TEM observing magnetic domains: Lorentz-TEM, electronic holography and differential phase contrast scanning TEM (DPC�睸TEM). Then we reviewed recent advances in magnetic domains imaging of a centrosymmetric magnet Fe3Sn2 by DPC-STEM. We demonstrated physical clarifications to “multiple topological states”, which are attributed to three-dimensional (3D) depth-modulated spin configurations, using DPC-STEM and 3D micromagnetic simulations. We then reported a new class of vortex-like spin configurations named “target bubble” and their field-driven magnetic evolutions in Fe3Sn2 nanodisks. Finally, we proposed a new strategy to design memory named Skyrmion-bubble-based memory, which utilizes Skyrmions and bubbles as binary bits “1” and “0”, respectively. Current-field-controlled topological Skyrmion�瞓ubble transformations have been also achieved. The novel magnetic domains and their intriguing electronic-magnetic properties shed by DPC-STEM are expected to facilitate advances in developing topology-related spintronic devices.