Dependence of crystallization processes of glass-forming melts on melt history: a theoretical approach to a quantitative treatment

摘要

A brief analysis of the spectrum of problems involved in the application of the basic ideas of classical nucleation theory to crystallization processes in glass-forming melts is given. The analysis covers the properties of critical clusters (whether they are identical to the properties of the evolving macroscopic phases or not) and, resulting from the respective assumptions, consequences with respect to critical cluster size and the work of critical cluster formation, the question as to whether viscosity or effective diffusion coefficients determine the kinetics of crystal formation and growth (the possible decoupling of diffusion and viscosity) or whether this process is realized by alternative mechanisms not studied in detail so far. Also covered are the problem of determining the size of the structural units in the expressions both for crystal nucleation and growth, and the problem as to what extent the thermodynamic and kinetic properties of glass-forming melts can be considered as a function of the actual thermodynamic state parameters of the systems under consideration. Applying the structural order parameter approach as developed by De Bonder, it is shown that the dependence of the properties of glass-forming melts on their history (or the dependence on the structural properties) can be given a definite quantitative interpretation.