Details
Original language | English |
---|---|
Pages (from-to) | 23-43 |
Number of pages | 21 |
Journal | Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties |
Volume | 74 |
Issue number | 1 |
Publication status | Published - Jul 1996 |
Externally published | Yes |
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.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
- Materials Science(all)
- Metals and Alloys
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In: Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties, Vol. 74, No. 1, 07.1996, p. 23-43.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - On the unique evaluation of local lattice parameters by convergent-beam electron diffraction
AU - Maier, H. J.
AU - Keller, R. R.
AU - Renner, H.
AU - Mughrabi, H.
AU - Preston, A.
N1 - 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
PY - 1996/7
Y1 - 1996/7
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0041113837&partnerID=8YFLogxK
U2 - 10.1080/01418619608239688
DO - 10.1080/01418619608239688
M3 - Article
AN - SCOPUS:0041113837
VL - 74
SP - 23
EP - 43
JO - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
JF - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
SN - 0141-8610
IS - 1
ER -