Study on some physical and optical properties of alkaline alumino borate glasses doped with Mn2+ ions

Abstract

Alkaline alumino borate glasses have composition (30-x) MO-xAl 2 O 3-69.5B 2 O 3-0.5MnO 2 (0 ≤ x≤ 15 mol %) (where MO=SrO, BaO). These glasses were prepared by melt quenching process. For these glasses, density was calculated using Archimedes principle. Variation in the density and molar volume was explained on the base of the bond length of Al-O and B-O. The values of polaron radius increases and field strength (F) decreases are attributed to the open structure. From optical absorption spectra, it was observed that broad absorption peak at 470 nm is due to the transition of Mn 3+ ions from 5 E g → 5 T 2g in the octahedral site. Optical band gap (E g) and Urbach energy (ΔE) were calculated. It results in the creation of non-bridging oxygens (NBO's) in the present glass system.