Role of manganese ions on the stability of ZnF2-P2O5-TeO2 glass system by the study of dielectric dispersion and some other physical properties

ZnF2-P2O5-TeO2 glasses containing different concentrations of MnO (ranging from 0 to 0.6%) were prepared. A number of studies, viz. differential thermal analysis, optical absorption, thermo luminescence, infrared spectra, magnetic susceptibility, elastic properties (Young's modulus Y, shear modulus n and micro hardness H) and dielectric properties (constant epsilon, loss tan delta, a.c. conductivity sigma(ac) over a range of frequency and temperature and dielectric breakdown strength), of these glasses were carried out as a function of manganese ion concentration. The analysis of the results indicate manganese ions mostly exist in Mn2+ state in these glasses when the concentration of MnO less than or equal to 0.4% and above this concentration manganese ions predominantly exist in Mn3+ state; from this analysis an attempt is made to identify the role of these ions on the stability of glass network. (C) 2002 Elsevier Science Ltd. All rights reserved.