Determination of Lattice Parameters of Polytypes in Liquid-Phase-Sintered SiC Using the Rietveld Method

Accurate determination of lattice parameters of polytypes in liquid‐phase‐sintered (LPS) SiC by conventional X‐ray powder diffractometry is difficult due to the severe overlap between different Bragg reflections and to the presence of geometrical aberrations. For this reason, results obtained by tra...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Ceramic Society 2004-05, Vol.87 (5), p.943-949
Main Authors: Hernández-Jiménez, Angel, Ortiz, Angel L., Sánchez-Bajo, Florentino, Guiberteau, Fernando, Cumbrera, Francisco L.
Format: Article
Language:English
Subjects:
Applied sciences
Building materials. Ceramics. Glasses
Ceramic industries
Ceramic sintering
Chemical industry and chemicals
Condensed matter: structure, mechanical and thermal properties
Exact sciences and technology
Hydrides, borides, nitrides, etc., and metalloidal compounds
Inorganic compounds
Materials science
Miscellaneous
Physics
Polymer processing
silicon carbide
sinter/sintering
Structure of solids and liquids
crystallography
Structure of specific crystalline solids
Technical ceramics
X-ray methods
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Accurate determination of lattice parameters of polytypes in liquid‐phase‐sintered (LPS) SiC by conventional X‐ray powder diffractometry is difficult due to the severe overlap between different Bragg reflections and to the presence of geometrical aberrations. For this reason, results obtained by traditional internal‐standard d‐spacing methods will be in general unrealistic. In this context, the Rietveld method, which is based on the refinement of a structural, profile, and instrumental model, is a more appropriate procedure to determine lattice constants of polytypes in these ceramics. Therefore, in this study we evaluated the accuracy of the results given by the Rietveld method for multiphase mixtures of SiC polytypes, when line broadening is dominated by the crystallite size. The accuracy was found to be remarkable, being sensitive to the number of polytypes but insensitive to the length of the lattice parameters and to the number of geometrical aberrations. In addition, an application to an LPS SiC specimen revealed the usefulness of the Rietveld method to better understand the microstructural evolution during sintering.
ISSN:0002-7820
1551-2916
DOI:10.1111/j.1551-2916.2004.00943.x