Physical properties of ZnF 2–As 2O 3–TeO 2 glasses doped with Cr 3+ ions

Abstract

Clear glasses of the system, ZnF 2–As 2O 3–TeO 2, containing different concentrations of Cr 2O 3 (ranging from 0 to 0.6 wt%) were prepared. A number of studies viz., differential thermal analysis, infrared spectra, optical absorption, ESR, magnetic susceptibility, thermoluminescence and dielectric properties (constant ε, loss tan δ , AC conductivity σ AC over a range of frequency and temperature and dielectric breakdown strength), on these glasses were carried out as a function of chromium ion concentration. Results have been analysed in the light of varying oxidation states of chromium ion; the analysis indicates a gradual conversion of chromium ions from Cr 3+ state to CrO 4 2− structural units (that take part in network forming positions) in the glass network, when Cr 2O 3 is present at higher concentrations (>0.3 wt%) in the glass matrix.