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

verfasst von
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.

Externe Organisation(en)
Universität Siegen
National Institute of Standards and Technology (NIST)
Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU Erlangen-Nürnberg)
University of Cambridge
Typ
Artikel
Journal
Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
Band
74
Seiten
23-43
Anzahl der Seiten
21
ISSN
0141-8610
Publikationsdatum
07.1996
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Elektronische, optische und magnetische Materialien, Allgemeine Materialwissenschaften, Physik der kondensierten Materie, Physik und Astronomie (sonstige), Metalle und Legierungen
Elektronische Version(en)
https://doi.org/10.1080/01418619608239688 (Zugang: Unbekannt)