Influence of nickel ions on dielectric and other physical properties of PbO–MoO3–B2O3 glass system

PbO–MoO3–B2O3 glasses containing various proportions of NiO (ranging from 0 to 1.0 mol %) have been prepared. A number of methods viz., differential thermal analysis, spectroscopic (IR and UV-Vis optical absorption, and ESR spectra) and dielectric properties (ε', tanδ, a.c. conductivity σac over a range of frequencies and temperatures) of these glasses has been employed in studies. The results of differential thermal analysis suggest a high glass forming ability for the glass containing 0.6 mol % of NiO. The studies of UV-Vis and IR spectra show that nickel ions occupy both tetrahedral and octahedral positions in the glass network with the dominance of the tetrahedral positions when the concentration of NiO is below 0.6 mol % in the glass matrix. The analysis of the results of studies of dielectric properties reveals that there is an increase in the rigidity and the dielectric breakdown strength of the glass when the concen-tration of NiO is around 0.6 mol %. Key words: PbO–MoO3–B2O3 glass; Ni2+ ions; DTA pattern; dielectric properties; ESR spectra; optical absorptio