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

The possibility of glass formation in the four-component system La 2 O 3 –Al 2 O 3 –B 2 O 3 –SiO 2 with La 2 O 3 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 SiO 2 , 8 – 25 Al 2 O 3 , and 32 – 50 B 2 O 3 — 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/cm 3 . 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.