Kinetics and size effect of isothermal crystallization in Li2B4O7 glass

We report the glass size dependency kinetics for isothermal process of the crystallization in lithium tetraborate (Li2B4O7:LBO) glass. We performed the X-ray and the isothermal differential scanning calorimetry (DSC) measurements of the LBO glass particles for samples sized 180–212 μm and <63 μm. The markedly different activation energies of crystallization for two species, 3.4 eV for the 180–212 μm glass and 4.4 eV for the <63 μm glass, respectively, indicate that the surface energy may be important in determining the activation energy. The Avrami exponent is also size-dependent and is thought to originate from the complex growth mechanism for small sized glass particles. Comparison of crystallization kinetics with in situ isothermal optical measurements is discussed.