Optical absorption and structure of impurity Ni2+ center in tungstate–tellurite glass

Absorption spectra of Ni2+ ions in 22WO3–78TeO2 tungstate–tellurite glass were studied and Ni2+ extinction coefficient spectral dependence was derived in the 450–2700 nm wavelength range. Computer modeling of the glass structure proved Ni2+ ions to be in trigonal-distorted octahedral environment in the tungstate–tellurite glass. Tanabe–Sugano diagram for such an environment was calculated and good description of the observed spectrum of Ni2+ ion was obtained. Basing on both absorption spectral range width and the extinction coefficient, nickel should be considered among the most strongly absorbing impurities in the tellurite glasses.

Research Highlights
► Ni2+ ions in tungstate-tellurite glasses.
► Experiment: Ni2+ absorption and extinction coefficient in 450–2700 nm range.
► Theory: Ni2+ center structure, electronic states, transitions, Tanabe-Sugano diagram.