The component dynamics of miscible binary mixtures of glass formers: New features

Abstract

Opposite effects on the width of the dispersion of the α-relaxation and the separation on the time scale of the Johari-Goldstein β-relaxation from the α-relaxation are predicted for guest molecules dissolved in a host, depending on whether the glass transition temperature of the host is higher or lower than that of the guest. These predictions are tested by dielectric relaxation measurements on mixtures of two glass-forming liquids. The results are in agreement with the predictions.

Keywords:

• disordered system
• glass transition
• dielectric relaxation
• binary mixtures

Acknowledgements

This work at the Università di Pisa was supported by MIUR-FIRB 2003 D.D.2186 grant RBNE03R78E. MST kindly acknowledges the support from MIUR (“Borse a favore di giovani ricercatori indiani”, n. 1451, 28/07/2005”). KLN was supported by the Office of Naval Research and a grant for International Semester Exchange Collaboration provided by International Materials Institute for New Functionality in Glass.