Atomic-scale structures in complex solids by Z-contrast STEM and first-principles theory

PDF Version Also Available for Download.

Description

Modern high-resolution scanning transmission electron microscopes are capable of forming electron probes below 2{angstrom}, sufficiently small to allow an atomic resolution Z-contrast image to be formed from many materials. Such images, formed with a high angle annular detector, are incoherent in nature, and can be described as a convolution of the probe intensity profile with an object function peaked sharply at the atomic sites. Unlike phase contrast microscopy, there is no phase problem associated with an incoherent image, and direct inversion to the projected atomic structure is possible. A quantitative method for structure retrieval is maximum entropy analysis, although under ... continued below

Physical Description

5 p.

Creation Information

Pennycook, S.J.; Pantelides, S.T.; Maiti, A.; Chisholm, M.F. & Yan, Y. February 1, 1998.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Authors

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Modern high-resolution scanning transmission electron microscopes are capable of forming electron probes below 2{angstrom}, sufficiently small to allow an atomic resolution Z-contrast image to be formed from many materials. Such images, formed with a high angle annular detector, are incoherent in nature, and can be described as a convolution of the probe intensity profile with an object function peaked sharply at the atomic sites. Unlike phase contrast microscopy, there is no phase problem associated with an incoherent image, and direct inversion to the projected atomic structure is possible. A quantitative method for structure retrieval is maximum entropy analysis, although under Scherzer incoherent conditions the probe tails are small, and peaks in the image intensity correspond closely to atomic positions. In such cases, an intuitive structure determination may be possible. Electron energy loss spectroscopy (EELS) may also be performed simultaneously, using the Z-contrast image to position the probe over selected atomic columns, providing complementary information on composition and electronic structure. On the theoretical side, present-day computers are now capable of electronic structure calculations that can be used to determine the preferred atomic arrangements in complex systems. Both first-principles and semiempirical approaches have been developed with complementary capabilities. Here the authors present several examples where a synergistic approach combining Z-contrast STEM, spatially resolved EELS and theoretical results have led to the elucidation of complex atomic structures. The ability to determine atomic structures experimentally to high accuracy provides both a perfect starting point for theoretical calculations and an ideal test of theoretical predictions. Theoretical studies can explore the new dimensions of time and energy. This combined approach leads to a detailed and comprehensive picture of complex atomistic mechanisms.

Physical Description

5 p.

Notes

OSTI as DE98005720

Source

  • 14. international congress on electron microscopy, Cancun (Mexico), 31 Aug - 4 Sep 1998

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Other: DE98005720
  • Report No.: ORNL/CP--97024
  • Report No.: CONF-980808--
  • Grant Number: AC05-96OR22464
  • Office of Scientific & Technical Information Report Number: 672117
  • Archival Resource Key: ark:/67531/metadc704593

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • February 1, 1998

Added to The UNT Digital Library

  • Sept. 12, 2015, 6:31 a.m.

Description Last Updated

  • Nov. 3, 2016, 7:01 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 2

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Pennycook, S.J.; Pantelides, S.T.; Maiti, A.; Chisholm, M.F. & Yan, Y. Atomic-scale structures in complex solids by Z-contrast STEM and first-principles theory, article, February 1, 1998; Tennessee. (digital.library.unt.edu/ark:/67531/metadc704593/: accessed December 16, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.