Three-phase structure invariants and structure factors determined with the quantitative convergent-beam electron diffraction method
-
Published:1999-03-01
Issue:2
Volume:55
Page:188-196
-
ISSN:0108-7673
-
Container-title:Acta Crystallographica Section A Foundations of Crystallography
-
language:
-
Short-container-title:Acta Cryst Sect A
Author:
Høier R.,Birkeland C. R.,Holmestad R.,Marthinsen K
Abstract
Quantitative convergent-beam electron diffraction is used to determine structure factors and three-phase structure invariants. The refinements are based on centre-disc intensities only. An algorithm for parameter-sensitive pixel sampling of experimental intensities is implemented in the refinement procedure to increase sensitivity and computer speed. Typical three-beam effects are illustrated for the centrosymmetric case. The modified refinement method is applied to determine amplitudes and three-phase structure invariants in noncentrosymmetric InP. The accuracy of the results is shown to depend on the choice of the initial parameters in the refinement. Even unrealistic starting assumptions and incorrect temperature factor lead to stable results for the structure invariant. The examples show that the accuracy varies from 1 to 10° in the electron three-phase invariants determined and from 0.5 to 5% for the amplitudes. Individual phases could not be determined in the present case owing to spatial intensity correlations between phase-sensitive pixels. However, for the three-phase structure invariant, stable solutions were found.
Publisher
International Union of Crystallography (IUCr)
Subject
Structural Biology
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献