Transparent glass-ceramics based on ZnO crystals

Glass-ceramics based on hexagonal ZnO crystals can be obtained in the SiO2-Al2O3-ZnO-K2O system. The materials can be highly transparent, with ZnO crystal sizes on the order of 5-20 nm dispersed uniformly throughout an alkali aluminosilicate glass. This is one of the few transparent yet relatively highly crystalline materials: based on a semiconductor crystal phase. The glass-ceramics are self-nucleating due to liquid-liquid phase separation and require no added nucleating agents. When doped with elements such as antimony or tin, these transparent glass-ceramics offer unique optical and dielectric properties, including high absorption in the near-infrared and high microwave susceptibilities.