Abstract
Focusing steps of an electron microscope, i.e., the change of focus, Δf, corresponding to one click on any one of the focus dials must be calibrated. Two methods have been used; measuring the distance between bright field and dark field images of small crystalline particles and measuring the diameters of optical diffractograms obtained from the image of an amorphous specimen.A new method utilizing the large depth of field in reflection electron microscopy (REM) provides a direct means of measuring the focusing steps on the micrograph. The in focus area in an REM image can be recognized as the “least grainy” part or the minimum contrast of images of steps. Using surface steps, particles, or other features as References, the shift of this in focus position due to the variation of objective lens current can be readily measured on the micrograph. This distance is then converted to f by taking account of magnification (calibrated) and the foreshortening factor (calculated from the diffraction pattern).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings, annual meeting, Electron Microscopy Society of America
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
