Rate of homogeneous nucleation in alkali disilicate glasses

TLDR: In this article, the authors measured the rate of crystal nucleation in alkali disilicate glasses by counting the number of crystals under an optical microscope and measured the viscosities of these glasses by the method of beam bending and penetration using the data of rate of nucleation and viscosity obtained in the present study and data of free energy measured by Takahashi and Yoshio.

Abstract: Rates of crystal nucleation in alkali disilicate glasses were measured by counting the number of crystals under an optical microscope The viscosities of these glasses were measured by the method of beam-bending and penetration Using the data of rate of nucleation and viscosity obtained in the present study and the data of free energy measured by Takahashi and Yoshio, crystal-glass interfacial energies for alkali disilicate systems were estimated on the basis of homogeneous nucleation theory as follows: 196 erg/cm2 for Li2O·2SiO2, 126–144 erg/cm2 for Na2O·2SiO2 and 88–104 erg/cm2 for K2O·2SiO2 The effects of the viscosity of glass, the free energy difference between crystal and glass and crystal-glass interfacial energy on the rate of nucleation were discussed, and the remarkably higher rate of crystal nucleation in the Li2O·2SiO2 glass was attributed to the larger free energy difference