Hostname: page-component-848d4c4894-ttngx Total loading time: 0 Render date: 2024-05-16T01:45:31.645Z Has data issue: false hasContentIssue false
  • English
  • Français

Crystal Phases and Lattice Dynamics of Slip-Cast β'-Sialons

Published online by Cambridge University Press:  10 February 2011

C.-K. Loong ,
J. W. Richardson Jr. ,
S. Suzuki  and
M. Ozawa
C.-K. Loong
Affiliation:
Argonne National Laboratory, Argonne, IL 60439, U. S. A.
J. W. Richardson Jr.
Affiliation:
Argonne National Laboratory, Argonne, IL 60439, U. S. A.
S. Suzuki
Affiliation:
Nagoya Institute of Technology, Tajimi, Gifu, 507, Japan.
M. Ozawa
Affiliation:
Nagoya Institute of Technology, Tajimi, Gifu, 507, Japan.
Get access

Abstract

The crystal structures and phonon densities of states (DOS) of β'-Sialon ceramics, Si6-zAlzOzN8-z (0 ≤ z ≤ 6), prepared by a novel slip-cast method were studied by neutron scattering techniques. A Rietveld analysis of the diffraction patterns shows that samples of z < 4 form a single-phase solid solution of Si-A1-O-N isostructural to β-Si3N4 (space group P63/m). Within this structure there is a consistent preferred occupation of 0 on the 2c sites and N on the 6h sites. For z > 4 the materials exhibit multiple-phase structure. The observed phonon DOS of the 0 ≤ z ≤ 4 ceramics displays phonon bands at about 50 and 115 meV. These features are considerably broader than the corresponding ones in β-Si3N4 powder. As z increases, effects due to atomic disorder lead to an overlap of the two phonon bands and a complete fill up of the phonon gap at ˜100 meV.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 410: Symposium S – Covalent Ceramics III-Science and Technology of Non-Oxides , 1995 , 241
Copyright
Copyright © Materials Research Society 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Jack, K. H., in Silicon nitride ceramics: scientific and technological advances (eds. Chen, I.-W., Becher, P. F., Mitomo, M., Petzow, G. and Yen, T.-S.) p. 15 (Materials Research Society, Pittsburgi, PA, 1993).Google Scholar
2 Ekström, T., in The encyclopedia of advanced materials (eds. Bloor, D., Flemings, M. C., Brook, R. J. and Mahajan, S.) p. 2444 (Pergamon, Oxford, 1994).Google Scholar
3 Ekstrtim, T. and Nygren, M., J. Am. Ceram. Soc., 75 259 (1992).Google Scholar
4 Lewis, M. H.. in Silicon nitride ceramics: scientific and technological advances (eds. Chen, I.-W., Becher, P. F., Mitomo, M., Petzow, G. and Yen, T.-S.) p. 159 (Materials Research Society, Pittsburgi, PA, 1993).Google Scholar
5 Suzuki, S., Nasu, T., Hayama, S., and Ozawa, M., J. Am. Ceram. Soc. (Submitted).Google Scholar
6 Gillott, L., Cowlam, N., and Bacon, G. E., J. Mat. Sci., 16 2263 (1981).Google Scholar
7 van Dijen, F. K., Metselaar, R., and Helmholdt., . B., J. Mat. Sci. Lett., 6 1101 (1987).Google Scholar
8 Loong, C.-K., Jr., J. W. Richardson, Ozawa, M.. and Sizuki, S., J. Am. Ceram. Soc. (submitted).Google Scholar
9 Loong, C.-K., Vashishta, P., Kalia, R. K., and Ebbsjö, I., Europhys. Lett., 31 (4). 201 (1995).Google Scholar
10 Wendel, J. A. and Goddard, W. A. III, J. Chem. Phys., 97 (7). 5048 (1992).Google Scholar
11 Mirgorodsky, A. P., Baraton, M. I., and Quintard, P.. Phvs. Rev., B 48 (18). 13326 (1993).Google Scholar