title: Study of point spread in the aberration-corrected transmission electron microscopy.
abstract: High precision determination of atomic position is necessary for quantitative electron microscopy so that small width of peaks, which represent atoms in structural images, adequate resolution, and sufficiently strong image contrast are needed. The width of peak is usually determined by the point spread (PS) of instruments, but the PS of objects should also be taken into consideration in aberration-corrected transmission electron microscopy when point resolution of a microscope reaches the sub-angstrom scale, and thus the PS of the instrument is comparable with that of the object. In this article, PS is investigated by studying peak width with variation of atomic number, sample thickness, and spherical aberration coefficients in both negative Cs (NCSI) and positive Cs imaging (PCSI) modes by means of dynamical image simulation. Through comparing the peak width with various atomic number, thickness, and values of spherical aberration, NCSI mode is found to be superior to PCSI considering the smaller width.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,People's Republic of China.
authors.forename: Binghui
authors.initials: B
authors.lastname: Ge
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,People's Republic of China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,People's Republic of China.
authors.forename: Yunjie
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yao