The influence of fluorine and nickel ions on the structural, spectroscopic, and optical properties of (100 − x)[15NaF–5CaF2–80B2O3]-xNiO glasses

Abstract

Borate glasses containing sodium fluoride and calcium fluoride were prepared. Nickel oxide was doped into the host glass in different ratios ranging from 0.05 to 1 wt%. Structural studies were exempted by Fourier transform infrared spectroscopy which suggested that the incorporation of fluorine ions in both BO3 and BO4 structural units tends to modify these units to form B–O–F linkage like BOF2 and BOF3, respectively. The glass structure is strongly affected by the ratio of nickel ions especially the infrared absorption region from 400 to 2000 cm−1. Nickel ions are favored to exist in octahedral states occupying the vacancies in the borate network. Optical transition is assumed to be direct transition according to the Yakupanoglu and Arslan procedure with acceptable error ratio about 4.5%. The density values are observed to increase linearly as the nickel ions increases.