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Title: Sub Angstrom imaging of dislocation core structures: How well areexperiments comparable with theory?

Abstract

During the past 50 years Transmission Electron Microscopy (TEM) has evolved from an imaging tool to a quantitative method that approaches the ultimate goal of understanding the atomic structure of materials atom by atom in three dimensions both experimentally and theoretically. Today's TEM abilities are tested in the special case of a Ga terminated 30 degree partial dislocation in GaAs:Be where it is shown that a combination of high-resolution phase contrast imaging, Scanning TEM, and local Electron Energy Loss Spectroscopy allows for a complete analysis of dislocation cores and associated stacking faults. We find that it is already possible to locate atom column positions with picometer precision in directly interpretable images of the projected crystal structure and that chemically different elements can already be identified together with their local electronic structure. In terms of theory, the experimental results can be quantitatively compared with ab initio electronic structure total energy calculations. By combining elasticity theory methods with atomic theory an equivalent crystal volume can be addressed. Therefore, it is already feasible to merge experiments and theory on a picometer length scale. While current experiments require the utilization of different, specialized instruments it is foreseeable that the rapid improvement of electron opticalmore » elements will soon generate a next generation of microscopes with the ability to image and analyze single atoms in one instrument with deep sub Angstrom spatial resolution and an energy resolution better than 100 meV.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Office of AdvancedScientific Computing Research. Office of Basic EnergySciences
OSTI Identifier:
903040
Report Number(s):
LBNL-59237
R&D Project: 503601; BnR: KC0201010; TRN: US200718%%364
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Philosophical Magazine; Journal Volume: 86; Journal Issue: 19-31; Related Information: Journal Publication Date: Oct-Nov 2006
Country of Publication:
United States
Language:
English
Subject:
75; ACCURACY; ATOMS; CRYSTAL STRUCTURE; DIMENSIONS; DISLOCATIONS; ELASTICITY; ELECTRONIC STRUCTURE; ELECTRONS; ENERGY RESOLUTION; ENERGY-LOSS SPECTROSCOPY; MICROSCOPES; SPATIAL RESOLUTION; STACKING FAULTS; TRANSMISSION ELECTRON MICROSCOPY

Citation Formats

Kisielowski, C., Freitag, B., Xu, X., Beckman, S.P., and Chrzan, D.C. Sub Angstrom imaging of dislocation core structures: How well areexperiments comparable with theory?. United States: N. p., 2005. Web.
Kisielowski, C., Freitag, B., Xu, X., Beckman, S.P., & Chrzan, D.C. Sub Angstrom imaging of dislocation core structures: How well areexperiments comparable with theory?. United States.
Kisielowski, C., Freitag, B., Xu, X., Beckman, S.P., and Chrzan, D.C. Fri . "Sub Angstrom imaging of dislocation core structures: How well areexperiments comparable with theory?". United States. doi:. https://www.osti.gov/servlets/purl/903040.
@article{osti_903040,
title = {Sub Angstrom imaging of dislocation core structures: How well areexperiments comparable with theory?},
author = {Kisielowski, C. and Freitag, B. and Xu, X. and Beckman, S.P. and Chrzan, D.C.},
abstractNote = {During the past 50 years Transmission Electron Microscopy (TEM) has evolved from an imaging tool to a quantitative method that approaches the ultimate goal of understanding the atomic structure of materials atom by atom in three dimensions both experimentally and theoretically. Today's TEM abilities are tested in the special case of a Ga terminated 30 degree partial dislocation in GaAs:Be where it is shown that a combination of high-resolution phase contrast imaging, Scanning TEM, and local Electron Energy Loss Spectroscopy allows for a complete analysis of dislocation cores and associated stacking faults. We find that it is already possible to locate atom column positions with picometer precision in directly interpretable images of the projected crystal structure and that chemically different elements can already be identified together with their local electronic structure. In terms of theory, the experimental results can be quantitatively compared with ab initio electronic structure total energy calculations. By combining elasticity theory methods with atomic theory an equivalent crystal volume can be addressed. Therefore, it is already feasible to merge experiments and theory on a picometer length scale. While current experiments require the utilization of different, specialized instruments it is foreseeable that the rapid improvement of electron optical elements will soon generate a next generation of microscopes with the ability to image and analyze single atoms in one instrument with deep sub Angstrom spatial resolution and an energy resolution better than 100 meV.},
doi = {},
journal = {Philosophical Magazine},
number = 19-31,
volume = 86,
place = {United States},
year = {Fri Dec 16 00:00:00 EST 2005},
month = {Fri Dec 16 00:00:00 EST 2005}
}