A new perspective for nucleation and nanocrystallization from interfacial energy and nanoscale composition fluctuations in glasses

Nucleation behaviors in glasses/supercooled liquids (SCLs) such as lithium disilicate Li2O-2SiO2, cordierite Mg2Al4Si5O18, fresnoite Ba2TiSi2O8, and K2O-Nb(2)O5-GeO2/TeO2 glasses were analyzed and discussed from the interfacial energy gamma at SCL-nucleus interfaces and nanoscale composition fluctuations. Based on the fragility concept for SCLs and the intrinsic origin of gamma, the magnitude order of gamma(fragile SCL) < gamma(strong SCL) was proposed to be a crucial guide for an understanding of high homogeneous nucleation rates and prominent nanocrystallization. The role of nucleating agent TiO2/ZrO2 in accelerating the nucleation rate in cordierite-based and beta-spodumene-type Li2O-Al2O3-SiO2-based glasses was discussed from the new perspective of gamma(homoepitaxial-like nucleation) < gamma(heteroepitaxial-like nucleation). Ferroelectric nanocrystals such as SrxBa(1-x)Nb(2)O(6) in borate glasses and fluoride nanocrystals such as CaF2 are also well understood from the proposed guidelines. The present article provides a new perspective for nucleation in glasses/SCLs, contributing to the comprehensive composition design of new innovative glass-ceramics.