Structural Details of Sialons — Their Influence on Phase Stability
In view of the importance for phase relationships, preparation and properties, details of the structures of O’-sialons and β’-sialons have been studied. In addition to conventional powder x-ray diffraction, more recently developed techniques have been used: Neutron powder diffraction for determination of site occupancies; MAS NMR and EXAFS to study local atomic arrangements. The results are compared to literature data from related work. It is proposed that there exists a certain degree of local ordering in O’- and β’-sialon structures, and that this sets limits on the ranges of solid solubility for the two phases. This may also affect the strength of sialon grains in the matrix.
Unable to display preview. Download preview PDF.
- 1.Jack, K.H., Silicon Nitride, Sialons and Related Ceramics. Ceramics and Civilisation, 1987, Vol III, 259–88.Google Scholar
- 5.Harris, R.K., Leach, M.J. & Thompson, D.P., Synthesis & MAS NMR of 15N-Enriched Silicon Nitride. Chem.Mater., 2, 320–23.Google Scholar
- 6.Lindqvist, O., Sjöberg, J., Hull, S. & Pompe, R., Structural Changes in O’-sialons, Si2-xAlxN2-xO1+x, 0.04≤x≤0.40. Acta Cryst. B, 1991, in press.Google Scholar
- 7.Sjöberg, J., Harris, R.K. & Apperley, D., A 29Si,27Al and 15N MAS NMR Study of O’-sialons and Some Related Phases. J.Mater.Chem., 1991, submitted for publication.Google Scholar
- 8.Sjöberg, J., Ericsson, T. & Lindqvist, O.,. The Local Structure of β’-sialons — an EXAFS Study. J.Mater.Sci., 1991, in preparation.Google Scholar
- 10.Sjöberg, J., O’Meara, C. & Pompe, R. J.Eur.Ceram.Soc., 1991, in preparation.Google Scholar
- 12.Loewenstein, W., The distribution of aluminium in the tetrahedra of silicates and aluminates. Am.Miner., 1954, 39, 92–96.Google Scholar