It should be something wrong with your TEM hardware. I often adust the ronchigram and its stigmation at about 10k magnification on the little screen. There is no obvios different with high magnification. And the contamention will be less in low magnification and easy to find amorphous area to do ranchigram and stigmator adustion.
原文由 fly-fall 发表:
when you rejusting ronchigram of STEM, please pay attention to the magnification. We find the ronchigram is unclear under 50K , but with a magnification about 500K, the ronchigram is obvious and can be seen directly by small screen or CCD.