On the unique evaluation of local lattice parameters by convergent-beam electron diffraction

authored by: H. J. Maier, R. R. Keller, H. Renner, H. Mughrabi, A. Preston
Abstract: We summarize some practical aspects of using convergent-beam electron diffraction (CBED) patterns for determination of three-dimensional lattice parameters in crystalline materials. Owing to the insensitivities of certain lattice spacings to changes in lattice parameters, and to measurement errors imposed by finite higher-order Laue zone (HOLZ) linewidths, most CBED patterns can be simulated by a number of different lattice parameter combinations. Unique combinations are found by fitting several patterns obtained from the same area. In cases where a unique set of all six parameters cannot be found, semiquantitative information about elastic stress and strain states can still be extracted. The number of obtainable lattice parameters is affected by the symmetry of the pattern and by the specific HOLZ reflections which are present, for a given accelerating voltage. Symmetry-breaking distortions in patterns from nominally orthorhombic systems can often be attributed to deviations in lattice angles as small as 0 01-0 02° away from 90°, even if such angular distortions are not expected from knowledge of the material’s bulk behaviour. The correct simulation of CBED patterns further requires consideration of foil thinning artefacts on HOLZ line positions. We show that an intelligent choice of zone axis can provide useful information even from difficult sample geometries.
External Organisation(s): University of Siegen
National Institute of Standards and Technology (NIST)
Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU Erlangen-Nürnberg)
University of Cambridge
Type: Article
Journal: Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
Volume: 74
Pages: 23-43
No. of pages: 21
ISSN: 0141-8610
Publication date: 07.1996
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, General Materials Science, Condensed Matter Physics, Physics and Astronomy (miscellaneous), Metals and Alloys
Electronic version(s): https://doi.org/10.1080/01418619608239688 (Access: Unknown)

BibTeX

@article{75199764fb1b4a5093ead386404888e3,
title = "On the unique evaluation of local lattice parameters by convergent-beam electron diffraction",
abstract = "We summarize some practical aspects of using convergent-beam electron diffraction (CBED) patterns for determination of three-dimensional lattice parameters in crystalline materials. Owing to the insensitivities of certain lattice spacings to changes in lattice parameters, and to measurement errors imposed by finite higher-order Laue zone (HOLZ) linewidths, most CBED patterns can be simulated by a number of different lattice parameter combinations. Unique combinations are found by fitting several patterns obtained from the same area. In cases where a unique set of all six parameters cannot be found, semiquantitative information about elastic stress and strain states can still be extracted. The number of obtainable lattice parameters is affected by the symmetry of the pattern and by the specific HOLZ reflections which are present, for a given accelerating voltage. Symmetry-breaking distortions in patterns from nominally orthorhombic systems can often be attributed to deviations in lattice angles as small as 0 01-0 02° away from 90°, even if such angular distortions are not expected from knowledge of the material{\textquoteright}s bulk behaviour. The correct simulation of CBED patterns further requires consideration of foil thinning artefacts on HOLZ line positions. We show that an intelligent choice of zone axis can provide useful information even from difficult sample geometries.",
author = "Maier, {H. J.} and Keller, {R. R.} and H. Renner and H. Mughrabi and A. Preston",
note = "Funding Information: ACICNOWLEDGMEWS Financial support by the Deutsche Forschungsgemeinschaft and the Volkswagen Stiftung are gratefully acknowledged. One of the authors (R.R.K.) additionally thanks the National Research Council Past-Doctoral Research Associateship",
year = "1996",
month = jul,
doi = "10.1080/01418619608239688",
language = "English",
volume = "74",
pages = "23--43",
journal = "Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties",
issn = "0141-8610",
publisher = "Taylor and Francis Ltd.",
number = "1",
}