Transparent and High Refractive Index La2O3-WO3 Glass Prepared Using Containerless Processing

Transparent and high refractive index 0.2La(2)O(3)center dot 0.8WO(3) glass was prepared in bulk form using containerless processing. The glass transition temperature, crystallization onset temperature, and melting temperature were 553 degrees C, 594 degrees C, and 1043 degrees C, respectively. The glass was colorless and widely transparent, in the visible to infrared region, indicating that the valence state of the W ion was 6. The refractive index was 2 in the visible range, and the Abbe number estimated from the Drude-Voigt relationship was 24. These results indicate that the La2O3-WO3 glass would be useful for optical applications in the visible to infrared region.