Three-Dimensional Measurement of Magnetic Moment Vectors Using Electron Magnetic Chiral Dichroism at Atomic Scale.
Three-Dimensional Measurement of Magnetic Moment Vectors Using Electron Magnetic Chiral Dichroism at Atomic Scale.
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DOI：
10.1103/physrevlett.127.087202
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发表时间：
2021-08
影响因子：
8.6
通讯作者：
Dongsheng Song;R. Dunin‐Borkowski
中科院分区：
文献类型：
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作者：
Dongsheng Song;R. Dunin‐Borkowski
在这里，我们已经开发了一种方法的三维（3D）的磁矩矢量在三个笛卡尔方向上使用电子磁性手征二向色性（EMCD）在原子尺度上的测量。在扫描透射电子显微镜（STEM）中，利用亚埃会聚电子束，在扫描原子平面的过程中，可以获得与束位相关的手征电子能量损失谱（EELS），该谱携带着三个笛卡尔方向的磁化强度信号。通过简单地移动EELS探测器，可以分别获得来自所有三个方向的原子分辨率EMCD信号。此外，使用离焦电子束可以显著增强EMCD信号，从而缓解特别是在原子分辨率下的低信号强度和信噪比的问题。我们提出的方法是兼容的设置广泛使用的原子分辨率STEM-EELS技术，并提供了一个简单的方法来实现在原子尺度上的新开发的无磁场TEM的三维磁测量。
Here we have developed an approach of three-dimensional (3D) measurement of magnetic moment vectors in three Cartesian directions using electron magnetic chiral dichroism (EMCD) at atomic scale. Utilizing a subangstrom convergent electron beam in the scanning transmission electron microscopy (STEM), beam-position-dependent chiral electron energy-loss spectra (EELS), carrying the EMCD signals referring to magnetization in three Cartesian directions, can be obtained during the scanning across the atomic planes. The atomic resolution EMCD signals from all of three directions can be separately obtained simply by moving the EELS detector. Moreover, the EMCD signals can be remarkably enhanced using a defocused electron beam, relieving the issues of low signal intensity and signal-to-noise-ratio especially at atomic resolution. Our proposed method is compatible with the setup of the widely used atomic resolution STEM-EELS technique and provides a straightforward way to achieve 3D magnetic measurement at atomic scale on newly developing magnetic-field-free TEM.