Pixelated detectors and improved efficiency for magnetic imaging in STEM differential phase contrast
Pixelated detectors and improved efficiency for magnetic imaging in STEM differential phase contrast
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DOI：
10.1016/j.ultramic.2016.03.006
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发表时间：
2016-06-01
期刊：
影响因子：
2.2
通讯作者：
McVitie, Stephen
中科院分区：
文献类型：
--
作者：
Krajnak, Matus;McGrouther, Damien;McVitie, Stephen
微分相衬成像技术在多晶磁性薄膜和纳米结构研究中的应用一直受到材料颗粒结构所产生的强烈衍射对比度的阻碍。在本文中，我们演示了如何像素化的检测器已被用来检测像差校正扫描透射电子显微镜（STEM）和随后的处理所获得的数据的明场磁盘允许有效地增强所得到的图像中的磁对比度。电荷耦合器件（CCD）相机的初步结果表明，这种改进比以前的方法的高效性。使用直接辐射探测器Medipix 3的进一步硬件开发也显示了与CCD相比收集时间减少超过一个数量级的可能性。我们表明，这使得亚像素测量的光束偏转由于磁感应。虽然检测和处理是数据密集型的，但我们已经证明了高效的DPC成像，从而实现了对感应变化的逐像素解释，具有纳米磁性成像的巨大潜力。(C)2016年6月，作者。由爱思唯尔公司出版
The application of differential phase contrast imaging to the study of polycrystalline magnetic thin films and nanostructures has been hampered by the strong diffraction contrast resulting from the granular structure of the materials. In this paper we demonstrate how a pixelated detector has been used to detect the bright field disk in aberration corrected scanning transmission electron microscopy (STEM) and subsequent processing of the acquired data allows efficient enhancement of the magnetic contrast in the resulting images. Initial results from a charged coupled device (CCD) camera demonstrate the highly efficient nature of this improvement over previous methods. Further hardware development with the use of a direct radiation detector, the Medipix3, also shows the possibilities where the reduction in collection time is more than an order of magnitude compared to the CCD. We show that this allows subpixel measurement of the beam deflection due to the magnetic induction. While the detection and processing is data intensive we have demonstrated highly efficient DPC imaging whereby pixel by pixel interpretation of the induction variation is realised with great potential for nanomagnetic imaging. (C) 2016 The Authors. Published by Elsevier B.V.