ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
Anisotropic peak broadening in hydrogen-cycled hexagonal LaNi5 and substitutional derivatives has been studied by means of synchrotron powder diffraction. The data have been analysed by a local lattice parameter variation method implemented in a Rietveld code and by an individual profile fitting using a dislocation peak broadening model. Two main dislocation systems, both with Burgers vector 1/3〈\bar{2}110〉, are activated by misfit of the lattice parameters between the intermetallic compounds and their hydrides. Two types of diffraction peak broadening effect were observed as a function of the substitution in LaNi5: (i) a decrease or disappearance of the broadening related to the decrease of the total dislocation density and (ii) a change in the anisotropy of the broadening related to the change of the nature of the dislocation system involved. The latter effect was attributed to a change in shape of the hydride precipitates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889800004556
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