Spectroscopic investigations on ZnF2-MO-TeO2 (MO = ZnO, CdO and PbO) glasses doped with chromium ions

Differential scanning calorimetric studies, spectroscopic studies (viz., optical absorption, ESR, infrared spectra) and thermoluminescence studies of ZnF2-MO-TeO2 (MO = ZnO, CdO and PbO) glasses doped with different concentrations of chromium ions have been investigated. Results have been analyzed in the light of different oxidation states of chromium ion. The analysis indicates chromium ions mostly exist in Cr3+ state in ZT, CT and PT glasses when Cr2O3 is present upto 0.1%, 0.2% and 0.3%, respectively; these ions seems to be present in Cr6+ state that take part network forming positions with CrO42- structural groups in all the three glasses when the concentration of Cr2O3 is greater than the above quantities. Quenching of thermoluminescence light output of the glasses has been observed with increase in Cr2O3 concentration upto 0.1%, 0.2% and 0.3%, respectively in ZT, CT and PT glasses. This has been identified due to the killing effect of Cr3+ ions. Further it has also been concluded that ZnF2-PbO-TeO2 is more favourable glass network for the presence of large concentration of laser-emitting Cr3+ ions, among the three glass series studied. (C) 2004 Elsevier Ltd. All rights reserved.