Image processing in high-resolution electron microscopy using the direct method. II. Image deconvolution

AbstractImage deconvolution is introduced as an effective tool to enhance the determination of crystal structures and defects in high-resolution electron microscopy. The essence is to transform a single image that does not intuitively represent the examined crystal structure into the structure image. The principle and method of image deconvolution together with the related image contrast theory, the pseudo weak phase object approximation (pseudo WPOA), are briefly described. The method has been applied to different types of dislocations, twin boundaries, stacking faults, and one-dimensional incommensurate modulated structures. Results on the semiconducting epilayers Si0.76Ge0.24/Si and 3C-SiC/Si are given in some detail. The results on other compounds including AlSb/GaAs, GaN, Y0.6Na0.4Ba2Cu2.7Zn0.3O7-δ, Ca0.28Ba0.72Nb2O6 and Bi2.31Sr1.69CuO6+δ are briefly summarized. It is also shown how to recognize atoms of Si from C based on the pseudo WPOA, when the defect structures in SiC was determined at the atomic level with a 200 kV LaB6 microscope.

Download Full-text

Image processing in high-resolution electron microscopy using the direct method.I.Phase extension

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767385000320 ◽

1985 ◽

Vol 41 (2) ◽

pp. 163-165 ◽

Cited By ~ 50

Author(s):

Hai-fu Fan ◽

Zi-yang Zhong ◽

Chao-de Zheng ◽

Fang-hua Li

Keyword(s):

Electron Microscopy ◽

Image Processing ◽

High Resolution ◽

High Resolution Electron Microscopy ◽

Resolution Electron

Download Full-text

Molecular imaging of Organo-Calcium salts by High Resolution Electron Microscopy and Image Processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181713 ◽

1990 ◽

Vol 48 (1) ◽

pp. 590-591

Author(s):

G. Miller ◽

J.R. Fryer ◽

W. Kunath ◽

K. Weiss

Keyword(s):

Electron Microscopy ◽

Image Processing ◽

High Resolution ◽

Low Dose ◽

High Resolution Electron Microscopy ◽

Unit Cell ◽

Recording Device ◽

Resolution Electron

Unfortunatly Wolfgang Kunath died January 1990High resolution electron microscopy and image processing are being used to determine the molecular packing within the crystal unit cell of the, organic-azo calcium salt. Due to the beam sensitive nature of the organic moiety which contains both aromatic and and aliphatic components, low dose techniques were used. This concisted of, searching the sample in the diffraction mode to find single crystals exibiting point like reflection to at least .2nm resolution, (fig. 1). Focusing and astigmatism correction was performed by moving the beam of the crystal (off axis). The beam was then moved on axis and a series of four, 10 e/A images taken, (fig. 2). Images were primarily recorded using an on line T.V. recording device. These images were then available for processing using the Semper image processing system. Two crystal orientations were found. Type 1 consisted of thin plate like crystals up to 5um diameter and generally 10nm to 20nm thick. Type 2 were thicker crystals with a 3.2nm lattice spacing. The power specrta of the first low dose images were calculated to asses the quality of the of the structural information present. For the type 1 crystal the power spectrum had to show at least second order reflections in two directions ( fig. 3 ). Type 2 crystals showed the 3.2nm reflection often down to the fith order. These crystals also showed parallel side bands corresponding to a d-spacing of about .8nm. With these results the unit cell was found to be tetragonal with a= .78nm b= 3.2nm c= .78nm. In accordance with the diffraction patterns exibited.

Download Full-text