Dielectric dispersion in the PbO-MoO3-B2O3 glass system

PbO-B2O3 glasses containing different concentrations Of MoO3 ranging from 0 to 4 mol% were prepared. The dielectric properties (constant epsilon', loss tan delta, a.c. conductivity or sigma(ac) over a range of frequency and temperature and breakdown strength) of these glasses have been studied. The results of these studies were analyzed with the aid of data on optical absorption, magnetic susceptibilities, ESR and IR spectra of these glasses. The analysis suggests that the molybdenum ions exist in Mo5+ state with MO(V)O-3- complexes that act as modifiers in addition to Mo6+ state with MoO4 and MoO6 structural groups in these glasses. Further the MO(V)O-3 - complexes were identified to exhibit dipolar relaxation effects. (C) 2004 Elsevier Ltd. All rights reserved.