Spectroscopic study of the influence of LaF3 admixture on the crystallization and structure of borosilicate glass

The effect of admixture of 6 mol% of LaF3 on the glass-forming characteristics and structural features of glasses in the Na2O–B2O3–SiO2 system has been investigated. Glasses have been obtained for B2O3/(Na2O + 3La2F6) ratio equal to 0.6, 0.8, 1.0 and 1.4 with and without La2F6, respectively.The phenomenon of LaF3 admixture on the structural changes and tendency to immiscibility and crystallization of the examined glasses was observed using FTIR and Raman spectroscopy and XRD. Raman spectra have shown that the ceramming process during heat treatment leads to crystallization of LaF3 only for some compositions of the glass. FTIR spectra have revealed changes in immiscibility which was enhanced with the increase of B2O3/(Na2O + 3La2F6) ratio for glasses with LaF3 admixture.