Effect of ZnAl2O4 crystallization on ion-exchange properties in aluminosilicate glass

ZnAl 2 O 4 nanocrystals (NCs) embedded transparent glass-ceramics containing relatively large amount of alkali oxide were prepared and effects of the crystallization on ion-exchange properties of glass-ceramics were investigated. Precipitation of ZnAl 2 O 4 NCs not only improves the Vickers hardness of the glass-ceramics, but also reduces the content of zinc and aluminum with concomitant increase in the content of sodium in the residual glassy phase. These changes in the residual glassy phase decrease the activation energy of K–Na ion-exchange and enhance the diffusion coefficient of potassium, resulting in the large ion-exchange depth and significantly improved Vickers hardness of the ion-exchanged glass-ceramics. These results show that glass-ceramics containing non-alkali nanocrystals have promising applications in fields of covers for optoelectronic devices. • ZnAl 2 O 4 NCs were precipitated in transparent aluminosilicate GCs containing large amount of alkali oxides. • Crystallization of ZnAl 2 O 4 NCs can improve ion exchange properties. • Compositional changes in residual glassy phase in GCs was responsible for the enhanced ion-exchange.