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.