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Comparison of Neutron Elastic and Inelastic Scattering from Fused Quartz, Cab-O-Sil and Aerogel

Published online by Cambridge University Press:  21 February 2011

John H. Root ,
William J. L. Buyers ,
John H. Page ,
Dale W. Schaefer  and
C. J. Brinker
John H. Root
Affiliation:
Atomic Energy of Canada Ltd., Chalk River, Ontario, Canada, KOJ 1JO
William J. L. Buyers
Affiliation:
Atomic Energy of Canada Ltd., Chalk River, Ontario, Canada, KOJ 1JO
John H. Page
Affiliation:
University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
Dale W. Schaefer
Affiliation:
University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
C. J. Brinker
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
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Abstract

Neutron scattering experiments have been performed to study the structure and dynamics of three preparations of silica: a dense glass (fused quartz), a flame-hydrolyzed aggregate (Cab-O-Sil, grade M5) and a polymeric aerogel. The experiments were performed on the three materials at temperatures selected from 300, 77 and 4.2 K. Neutron inelastic scattering was measured at Q = 2.5, 2.9 and 4.0 Å−1.

The elastic scattering indicates a systematic decrease in positional correlations on progressing from fused quartz through Cab-O-Sil to aerogel. The inelastic scattering was analyzed with the Buchenau model [1] to obtain the sample, Q and temperature dependences of the density of states, g(v). In the aerogel g(v) increases with temperature at frequencies greater than 1.5 THz and is enhanced at Q = 2.5 Å−1. Thus a complete explanation of the inelastic scattering from aerogels must account for multiphonon processes, local antiphase motions and anharmonic effects.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 166: Symposium J – Neutron Scattering for Materials Science , 1989 , 379
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1. Buchenau, U., Z. Phys. B58, 181 (1985).Google Scholar
2. Buchenau, U., Prager, M., Nücker, N., Dianoux, A.J., Ahmad, N. and Phillips, W.A., Phys. Rev. B34, 5665 (1986).Google Scholar
3. Buchenau, U., Zhou, H.M., Nucker, N., Gilroy, K.S. and Phillips, W.A., Phys. Rev. Lett. 60, 1318 (1988).CrossRefGoogle Scholar
4. Kjems, J.K., Freltoft, T., Richter, D. and Sinha, S.K., Physica 136B, 285 (1986).Google Scholar
5. Freltoft, T., Kjems, J. and Richter, D., Phys. Rev. Lett 59, 1212 (1987).CrossRefGoogle Scholar
6. Page, J.H., Buyers, W.J.L., Dolling, G., Gerlach, P. and Harrison, J.P., Phys. Rev B39, 6180 (1989).CrossRefGoogle Scholar
7. Vacher, R., Woignier, T., Pelous, J., Coddens, G. and Courtens, E., Europhys. Lett. 8, 161 (1989).Google Scholar
8. Reichenauer, G., Fricke, J. and Buchenau, U. Europhys. Lett. 8, 415 (1989).CrossRefGoogle Scholar
9. Schaefer, D.W., Brinker, C.J., Wilcoxon, J.P., Wu, D.Q., Phillips, J.C. and Chu, B., MRS Symp. Proc. 121, 691 (1988).Google Scholar
10. Richter, D., Passell, L., Phys. Rev B26, 4078 (1982).Google Scholar
11. Schaefer, D.W., Brinker, C.J., Richter, D., Farago, B. and Frick, B., preprint.Google Scholar