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Time and Ensemble Averaged Dynamic Light Scattering in Orthoterphenyl Above and Below the Glass Transition

Published online by Cambridge University Press:  10 February 2011

D. L. Sidebottom
Affiliation:
Advanced Materials Lab, 1001 Univ. Blvd. SE, Albuquerque, NM 87106
C. M. Sorensen
Affiliation:
Department of Physics, Kansas State University, Manhattan, KS 66506–2601
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Abstract

While traditional dynamic light scattering is useful for following structural relaxation in the liquid, in the glassy domain the technique is limited by the ultimate patience of the experimentalist; i.e., the structural relaxation can not be measured when the experimental time scale is less than the structural relaxation time. Nevertheless, we show how useful information regarding structural relaxation can be accessed from light scattering in the glass using a novel ensemble-averaged technique. Dynamic light scattering (DLS) measurements performed on glass forming orthoterphenyl show an inequality between time and ensemble average correlation functions near and below the calorimetrie glass transition temperature, Tg, and hence demonstrate ergodicity breaking. Our ensemble averaged measurements provide a measure of the so-called non-ergodicity parameter, fq, below Tg. Our DLS results for orthoterphenyl indicate that the functional form for fq is consistent with Mode Coupling theory predictions, but occurs at the glass transition temperature, Tg≈243K, rather than at TC≈290K as observed in neutron scattering studies.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCES

1.Relaxations in Complex Systems, Proceedings of the Workshop on Relaxation Processes,” Blacksburg VI, 1983, edited by Ngai, K. and Smith, G.B. (National Technical Information Service, U.S. Department of Commerce, Washington, DC, 1985).Google Scholar
2. Dynamics of Disordered Materials, edited by Richter, D., Dianoux, A.J., Petry, W. and Teixeria, J. (Springer-Verlag, Berlin, 1989).Google Scholar
3. Leutheusser, E., Phys. Rev. A29, 2765 (1984).Google Scholar
4. Bengtzelius, U., Gotze, W. and Sjolander, A., J. Phys. C19, 5915 (1984).Google Scholar
5. Das, S.P. and Mazenko, G.F., Phys. Rev. A34, 2265 (1986).Google Scholar
6. Gotze, W. and Sjogren, L., J. Phys. C20, 879 (1990).Google Scholar
7. Sjogren, L., Z. Phys. B79, 5 (1990).Google Scholar
8. Gotze, W. and Sjogren, L., Rep. Prog. Phys. 55, 241 (1992).Google Scholar
9. Taborek, P., Kleimann, R.N., and Bishop, D.J., Phys. Rev. B34, 1835 (1986).Google Scholar
10. Richter, D., Frick, B., and Farago, B., Phys. Rev. Lett. 61, 2465 (1988); andGoogle Scholar
Richter, D., Frick, B., and Farago, B., Phys. Rev. Lett. 64, 2921 (1990).Google Scholar
11. Bartsch, E., Fujara, F., Kiebel, M., Sillescu, H., and Petry, W., Ber. Bunsenges. Phys. Chem. 93, 1252(1989).Google Scholar
12. Elmroth, M., Borjesson, L., and Torreil, L.M., Phys. Rev. Lett. 68, 79 (1992).Google Scholar
13. Dreyfus, C., Lebon, M.J., Cummins, H.Z., Toulouse, J., Bonello, B., and Pick, R.M., Phys. Rev. Lett. 69, 3666 (1992).Google Scholar
14. Tao, N.J., Li, G., Cummins, H.Z., Phys. Rev. Lett. 66, 1334 (1991);Google Scholar
Li, G., Du, W.M., Chen, X.K., Cummins, H.Z. and Tao, N.J., Phys. Rev. A45, 3867 (1992);Google Scholar
Li, G., Du, W.M., Sakai, A., and Cummins, H.Z., Phys. Rev. A46, 3343 (1992).Google Scholar
15. Yang, Y. and Nelson, K.A., Phys. Rev. Lett. 74, 4883 (1995).Google Scholar
16. Steffen, W., et al., Phys. Rev. E49, 2992 (1994).Google Scholar
17. Greet, R.J. and Turnbull, D., J. Chem. Phys. 46, 1243 (1967).Google Scholar
18. Laughlin, W.T. and Uhlmann, D.R., J. Phys. Chem. 76, 2317 (1972); andGoogle Scholar
Cukiermann, M., Lane, J.W., and Uhlmann, D.R., J. Chem. Phys. 59, 3639 (1973).Google Scholar
19. Pusey, P.N. and van Megen, W., Physica A157, 705 (1989).Google Scholar
20. Pusey, P.N., Vaughan, J.M. and Willetts, D.V., J. Opt. Soc. Am. 73, 1012 (1983).Google Scholar
21. Berne, B. and Pecora, R., Dynamic Light Scattering (Wiley, New York, 1976).Google Scholar
22. Ren, S.Z. and Sorensen, C.M., Phys. Rev. Lett. 70, 1727 (1993).Google Scholar
23. Joosten, J.G.H., McCarthy, J.L., and Pusey, P.N., Macromolecules 24, 6690 (1991).Google Scholar
24. Xue, J.Z., Pine, D.J., Milner, S.T., Wu, W.L., Chaikin, P.M., Phys. Rev. A46, 6550 (1992).Google Scholar
25. Schatzel, K., Appl. Opt. 32, 3880 (1993).Google Scholar
26. Fytas, G., Wang, C.H., Lilge, D., and Dorfmuller, Th., J. Chem. Phys. 75, 4247 (1981).Google Scholar
27. Taylor, T.W. and Sorensen, C.M., Appl. Optics 25, 2421 (1986).Google Scholar