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The geometrical distortion of deficiency conic sections and its influence on lattice‐parameter determinations
Author(s) -
Lutts A.
Publication year - 1973
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889873009179
Subject(s) - misorientation , lattice (music) , lattice constant , lattice plane , condensed matter physics , optics , geometry , diffraction , mathematics , physics , materials science , mathematical analysis , computational physics , reciprocal lattice , chemistry , crystallography , microstructure , acoustics , grain boundary
The lattice‐parameter error due to a relative misorientation between the specimen and the flat film in the transmission divergent X‐ray beam and Kossel techniques developed for α‐iron has been studied in detail. It has been shown that the most frequently encountered case of film misorientation can be theoretically divided into two pure components. The Type I component has been shown to have no influence whatsoever on the lattice parameter measured by this or any other method involving the ratio technique. The lattice‐parameter error is thus due exclusively to the Type II component. In addition, it has been shown that these errors, which can become relatively important, are present in all linearly non‐symmetric methods. In contrast, errors due to Type II components in linearly symmetrical methods should be very small if not experimentally undetectable. The geometry involved is such that the lattice parameter error cannot be experimentally determined. However, such film misorientations and their resulting lattice‐parameter errors can be reduced to a very low value by means of the reticule method previously proposed and described.