High barium content lead and alkaline-free glasses

•A new family of glasses free of alkaline, chemically stable has been fabricated.•These glasses have high Barium content (54 Mol.%) and high refraction index (>1.6).•They have been fabricated at workable melting temperature, using low cost materials.•The obtained glasses can be considered very promising materials for optical systems.•They are very competitive versus the ones based on expensive rare-earth.

Four glass compositions of the system BaO-Al2O3-SiO2 with high content of BaO>50% mol and with B2O3 addition (3–10 wt%) were melted at 1400 °C. The effect of alkaline earth BaO oxide on the glass phase separation and on refraction index n is investigated. IR and MAS-NMR spectroscopy are used for structural characterization. Finally stable alkaline free glasses with a content of BaO ranging from 47.4 Mol.% to 54.5 Mol.% and with a n=1.62±0.01 at 468.1 nm have been obtained.