Large‐sized La sub 2/sub2 O sub 3/sub3 ‐TiO sub 2/sub2 high refractive glasses with low SiO sub 2/sub2 fraction by hot‐press sintering

摘要

Abstract Owing to the ultrahigh refractive index, La 2 O 3 ‐TiO 2 glass is regarded as a promising candidate material in the field of lens, gemstones, and many other optics. However, due to its extremely low glass‐forming ability, it can only be obtained by rapid solidification processes such as melt quench or containerless solidification methods, leading to the limited size of as‐solidified products (for example, 1‐10?mm for containerless solidified sample), that are severely deferring the application of this novel high refractive glass. In this work, we aimed at preparing the larger sized bulk glasses over 10?mm, La 2 O 3 ‐TiO 2 glasses were successfully prepared by hot‐press sintering within the glass kinetic window. A small amount addition of SiO 2 was found to effectively increase the glass‐forming ability while keeping high refractive index. When the content of SiO 2 was 15?mol%, its transmittance could reach 54% at 800?nm and 72% in the infrared region (1?mm thick). Meanwhile, its refractive index could keep ultrahigh value above 2.14. And the sintering mechanism was studied according to the sintering shrinkage curve. It indicates that the plastic flow was the main mass transfer way in the densification process.