Spot auto-focusing and spot auto-stigmation methods with high-definition auto-correlation function in high-resolution TEM
Spot auto-focusing and spot auto-stigmation methods with high-definition auto-correlation function in high-resolution TEM
复制标题
高分辨率TEM中具有高清自相关功能的光斑自动聚焦和光斑自动去污方法
DOI：
10.1093/jmicro/dfy001
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发表时间：
2018
期刊：
影响因子：
1.8
通讯作者：
Shigeto Isakozawa Taishi Fuse Junpei Amano Norio Baeeba
中科院分区：
文献类型：
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作者：
Yong-Il Ko; Cheon-Soo Kang; Eun-Ae Shin; Yong Chae Jung; Hiroyuki Muramatsu; Takuya Hayashi; Yoong Ahm Kim; Mildred S. Dresselhaus;T. Komatsu;Shigeto Isakozawa Taishi Fuse Junpei Amano Norio Baeeba
作为高分辨透射电子显微术中基于衍射图的方法的替代方案，提出了一种具有独特的高清晰度自相关函数（HD-ACF）的光斑自聚焦（AF）方法和光斑自消像散（AS）方法。HD-ACF清楚地解决了ACF中心峰区域在小的非晶薄膜图像，反映了相衬传递函数。在120 kV透射电子显微镜的300 k放大率下，AF使用的最小面积为64 × 64像素（约3 nm 2），AS使用的最小面积为256 × 256像素。这些方法的一个有用的优点是，即使对于低s/n（~1.0）图像，AF功能也具有允许的精度。为了使用这些方法，必须准备关于通过预采集离焦非晶薄膜图像的HD-ACF的散焦依赖性的参考数据库。这可能是非常有益的，因为样本不限于弱相位物体的近似，而是可以扩展到这种近似之外的物体。
As alternatives to the diffractogram-based method in high-resolution transmission electron microscopy, a spot auto-focusing (AF) method and a spot auto-stigmation (AS) method are presented with a unique high-definition auto-correlation function (HD-ACF). The HD-ACF clearly resolves the ACF central peak region in small amorphous-thin-film images, reflecting the phase contrast transfer function. At a 300-k magnification for a 120-kV transmission electron microscope, the smallest areas used are 64 × 64 pixels (~3 nm2) for the AF and 256 × 256 pixels for the AS. A useful advantage of these methods is that the AF function has an allowable accuracy even for a low s/n (~1.0) image. A reference database on the defocus dependency of the HD-ACF by the pre-acquisition of through-focus amorphous-thin-film images must be prepared to use these methods. This can be very beneficial because the specimens are not limited to approximations of weak phase objects but can be extended to objects outside such approximations.