Glass transition in inorganic glasses, polymers, and crystals

Abstract

Abstract Main features of classical inorganic (window) glasses, polymeric glasses, and disordered phases in crystals and crystalline materials treated as glasses are briefly described and compared. The glass transition in crystals and crystalline materials is often combined with a phase transition. Both the transitions are characterized by divergency of relaxation time τ. A simple method, based on the concepts of nonequilibrium thermodynamics, is used to distinguish between the different reasons of the divergency at phase and glass transition. Transition in a rubber-like polymer is taken as an example of a pure glass transition. The complex permittivity behaviour in this transition is described and used as a demonstration of a typical susceptibility behaviour (relaxation behaviour) in a glass transition region. Permittivity behaviour of crystal and crystalline glasses is compared with that of polymers. It is supposed that the relaxation behaviour of some plastic crystals may be described as pure glass tra...