Glass-forming ability of high refractive index amorphous materials prepared by -TiO2 and Nb2O5

By using a laser pneumatic suspension furnace, a series of transparent 0.3LaGaO(3)-(0.7 -x)TiO2-xNb(2)O(5) amorphous spheres with diameters of approximately 2-4 mm can be obtained with an x-value between 0 and 0.65. An approximate value for the critical cooling rate was obtained using CCT diagrams. The four criterions of GFA (glass forming ability) were discussed in terms of the R-2 value; the higher the R-2 value, the better the linear relationship between GFA and the critical cooling rate. The maximum value of R-2 was obtained for the Rc-Delta T (Rc is defined as the critical cooling rate) plot. The Delta T was chosen as a GFA criterion to evaluate the GFA of LaGaO3- TiO2, LaGaO3-Nb2O5 and LaAlO3-Nb2O5 amorphous spheres. The GFA of four series of highly-refractive amorphous spheres prepared by TiO2 and Nb2O5 are also discussed. The maximum transmittances of 0.3LaGaO(3)-(0.7 -x)TiO2-xNb(2)O(5) amorphous samples, where x = 0.1, 0.2 and 0.3, were approximately 78%, 76% and 75% respectively. The refractive index nd of the amorphous samples were all higher than 2.2.

Automated summary

A series of transparent amorphous spheres composed of LaGaO3, TiO2, and Nb2O5 were successfully obtained using a laser pneumatic suspension furnace, and their glass forming ability (GFA) and optical properties were studied. The study revealed a linear relationship between GFA and critical cooling rate, with higher R-2 values indicating better GFA. The maximum transmittances of the samples were found to be around 75-78%, with refractive indices exceeding 2.2.