Eu3+ and Ce3+ co-doped aluminosilicate glasses and transparent glass-ceramics containing gahnite nanocrystals

- Transparent zinc-aluminosilicate glass-ceramics doped with Ce3+ and Eu3+.
- Formation of gahnite phase with RE occupancy.
- Anomalous infrared emission of Ce3+.
- Color tenability in the red or blue spectral region.

Transparent zinc-aluminosilicate glass-ceramics containing cerium and europium ions were prepared by controlled thermal heating of parent glasses. Addition of CeO2 resulted in the improved transparency of the glasses in the visible spectral region. X-ray diffraction patterns of the glass-ceramics indicate the formation of the crystalline gahnite phase and there are evidences of Ce3+ and Eu3+ occupancies in this phase, as well as co-existence in the amorphous phase. Ce3+ emission corresponding to the allowed f-d transitions is identified, as well as an anomalous emission in the red-infrared region. The characteristic luminescence of Eu3+ in the red is observed. Judd-Ofelt analysis of Eu3+-doped samples reveals enhanced site asymmetry around the ion and a high branching ratio for the 612 nm emission after ceramization. Due to enhanced Ce3+ emission and Eu3+ emission quenching, color tunability is possible in the red to blue spectral region, depending on the heat treatment duration.