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

Abstract Nucleation behaviors in glasses/supercooled liquids (SCLs) such as lithium disilicate Li 2 O–2SiO 2 , cordierite Mg 2 Al 4 Si 5 O 18 , fresnoite Ba 2 TiSi 2 O 8 , and K 2 O–Nb 2 O 5 –GeO 2 /TeO 2 glasses were analyzed and discussed from the interfacial energy γ at SCL–nucleus interfaces and nanoscale composition fluctuations. Based on the fragility concept for SCLs and the intrinsic origin of γ , the magnitude order of γ (fragile SCL) < γ (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 TiO 2 /ZrO 2 in accelerating the nucleation rate in cordierite‐based and β‐spodumene‐type Li 2 O–Al 2 O 3 –SiO 2 ‐based glasses was discussed from the new perspective of γ (homoepitaxial‐like nucleation) < γ (heteroepitaxial‐like nucleation). Ferroelectric nanocrystals such as Sr x Ba 1– x Nb 2 O 6 in borate glasses and fluoride nanocrystals such as CaF 2 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.