Defocus step size of the LBNL One Angstrom Microscope

O' ; Keefe, Michael A. ; Nelson, E. Chris

Lawrence Berkeley National Laboratory

关键词: Defocus Variation Sub-Angstrom;    36 Materials Science;    Electron Microscopes;    Lawrence Berkeley Laboratory Defocus Variation Sub-Angstrom;    Microscopes;   

DOI  :  10.2172/817235
RP-ID  :  LBNL/PUB--3170
RP-ID  :  AC03-76SF00098
RP-ID  :  817235

美国|英语

来源: UNT Digital Library

【 摘 要 】

The change in focus of a high-resolution electron microscope is generally assumed to be linear with change in objective lens current. Thus the defocus step size should be constant for a constant step in lens current. Measurements on the LBNL One-Angstrom Microscope show that the step size increases with increasing underfocus (reduced lens current). Differentiation of the best-fit quadratic shows that the defocus step size varies linearly as defocus changes.