Study on the influence of TiO2 on the insulating strength of ZnO–ZnF2–B2O3 glasses by means of dielectric properties

ZnO–ZnF2–B2O3 glasses containing small concentrations of TiO2 ranging from 0 to 0.6 mol% were prepared. Dielectric properties (constant ε′, loss tan δ, ac conductivity σac over a moderately wide range of frequency and temperature at room temperature in air medium) of these glasses have been studied. The results of these studies were analyzed with the aid of data on optical absorption, ESR and IR spectra of these glasses. The analysis suggests that when the concentration of TiO2>0.2 mol%, the titanium ions, in addition to Ti4+ state, co-exist in Ti3+ state, act as modifiers and reduce the breakdown strength.