Nucleation in oxide glasses: comparison of theory and experiment

Experimental nucleation rates on eight oxide glasses crystallizing polymorphously are analysed in terms of non–classical nucleation theories, including phenomenological and density functional approaches. It is demonstrated that of the six non–classical models considered here, only the semiempirical density functional approach and the phenomenological diffuse interface theory are fully consistent with the data. The other models (the self–consistent classical theory, the detailed molecular theories and a Ginzburg–Landau/Cahn–Hilliard model) did not provide a satisfactory fit with experiment. The failure/success of these approaches is discussed in terms of the applied approximations.