In-depth analysis of MoO3–CaF2–Bi2O3–B2O3–Cr2O3 glass system using physical, optical, Raman and FTIR characterizations

With the interest to study the structural, optical and spectroscopic properties of the molybdenum and calcium fluoride co-doped bismuth borate glasses added with small trace of chromium ions, a detailed investigation has been carried out. The samples with the formula xMoO₃-(20-x)CaF₂-20Bi₂O₃-59.8B₂O₃-0.2Cr₂O₃ were prepared by adopting melt-quench method. XRD, optical absorption, FTIR and Raman characterizations were studied for the glass samples and discussed elaborately. XRD reveals the amorphous nature of the prepared samples with broad hump. The density of the samples was calculated and reported an increase from 3.97 gm/cc to 4.203 gm/cc with increase in MoO₃ content. Similarly, the optical energy band gap also increase from 1.87 eV to 2.26 eV and is attributed to the decrease in NBO's. The refractive index of the glass samples in the range of 2.63–2.79 opens up applications in non-linear optical and opto-electronics devices. FTIR spectra in hand with Raman spectra provides evidence to the increase in compactness with increase in MoO₃ content, as there is a conversion of BO₃ to BO₄ units. The other probable structure units in the glass network include MoO^2-₄ and MoO₆ units resulting in structural stability.