Enhanced optical and structural features of Ni2+/La3+ hybrid borate glasses.

Glasses with the formula [80B2O3-4.0La2O3-(16-x) PbO-xNiO, (x ranged from 0.0 to 4.0 mol%)], were produced by the standard quenching method. XRD, SEM and EDAX analysis established the success of the obtained samples preparation. Density measurements and FT-IR analysis confirmed the structural modifications emerging by the entry of Ni2+ ions as a network modifier, where the structural unit's ratio of BO3 (BO4) was affirmed to increase (decrease) with a gradual rise of NBO's number. The semiconducting behavior of the current glassy samples was verified by the role of the structural modifications in decreasing the gap energy and increasing both Urbach and mineralization criterion. Ligand field analysis applied to the absorption spectra exhibited the covalent nature of the Ni2+ bonds. The behavior of electronic polarizability supported the gradual increases of the linear and non-linear refractive index of the samples. These properties qualify the present glasses as an optically active material for the devices operated in the visible-NIR regions.