Evolution of Disordering in SiC upon Sintering; Phase Analysis of SiC by Rietveld Method with Application of Neutron and X-Ray Diffraction |
| B. Pałosz High Pressure Research Center, Polish Academy of Sciences, Sokołowska 29, 01-142 Warszawa, Poland H. Boysen, J. Schneider and H. Schulz Institut für Kristallographie und Mineralogie der Universität, Theresienstrasse 41, 8000 München 2, Germany |
| Dedicated to Professor Dr. Julian Auleytner on the occasion of his 70th birthday |
| Received: September 18, 1992 |
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| Neutron and X-ray diffraction patterns of α and β powders as well as of sintered SiC were analysed by a multiphase Rietveld method. It is shown that structural models combined of large period polytypes can be used to approximate the disordering of these polytype structures. The hexagonality of the samples could be terminated with reproducibility 1-2% using different combinations of large-period polytypes. It follows that the usual classification into α and β SiC is an oversimplification. The polytype behaviour of SiC powders and the role of twinning of cubic layer stackings is discussed. Distribution functions of stacking sequences of different length in α and β phases are derived. |
| DOI: 10.12693/APhysPolA.83.95 PACS numbers: 61.10.My, 61.12.-q, 61.50.Ks, 81.20.Lb |