Critical dynamics of dipolar glasses
Institut für Theoretische Physik,
Georg-August-Universität, Bunsenstrasse 9, D-37073 Göttingen, Germany
Accepted: 21 June 1996
We discuss the critical dynamics of dipolar glasses as observed in the dynamic dielectric response and the dynamic structure factor. Our analysis is based on a hydrodynamic model, generalized to include slow (dipolar) fluctuations near the glass transition. The critical slowing-down of the dipoles gives rise to anomalies in the dynamic dielectric response, the appearance of a central peak and a divergent sound damping. All three phenomena are interrelated and determined by the critical exponents of an Ising spin glass. We work out the consequences of a dynamic scaling hypothesis for the dipolar autocorrelation and discuss two examples of such a scaling function. One is calculated within mean-field theory and the other is taken from numerical simulations. We compare our results to recent experiments on .
PACS: 64.70.Pf – Glass transitions / 64.60.Ht – Dynamic critical phenomena
© EDP Sciences, 1996