请教如何调试电镜才能得到高分辨的STEM图像

样品事先用plasma cleaning
扫描速度不要上来就是最慢的,或者在非目标区聚焦,,聚好移过去.

procedres
1. plasma cleaning
2. good alignment of TEM in the nanoprobe(FEI Tecnai TEM) mode
especially, alignment of the C2 aperture and rotation center
3. aligned instruments by Ronchigram, including stigmatism & C2 aperture & focus
4. Magnification >= 5M X