FTIR and UV spectra of pentaternary borate glasses

A series of (75-x) B2O3-xBi2O3-10Na2O-10CaO-5Al2O3 glasses, (0 ≤ x ≤ 25 mol%) were prepared. Density and molar volume were measured. FTIR and UV spectra were recorded at 400-4000 cm−1 and 200-850 nm, respectively. Optical energy gap (Eopt.), Urbach's energy (Eu), and refractive index (n) were calculated using absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods. Molar refraction (Rm) and molecular polarizability (αm) have been calculated according to (ASF) method.