Investigation of Glass Formation and the Properties of Lanthanum-Aluminum-Borosilicate Glasses with High Lanthanum Oxide Content

Abstract

The possibility of glass formation in the four-component system La₂O₃–Al₂O₃–B₂O₃–SiO₂ with La₂O₃ molar content 27% was studied. The ratios of the components for which the glasses are most stable with respect for amorphous phase separation and crystallization were determined. The composition range bounded by the limit values of the molar content of the components — 7 – 30 SiO₂, 8 – 25 Al₂O₃, and 32 – 50 B₂O₃ — makes it possible to obtain glass with refractive index n_D to 1.74, dispersion coefficient v_D to 57, and density ≤ 4.15 g/cm³. The manufacturability of these glasses creates the prerequisites for developing materials with different combinations of optical constants by modifying the matrix with a wide range of dopants.