Correlated EPR and optical study of charge trapping phenomena in tellurite glasses. The role of barium oxide

Tellurite glasses of the compositions TeO2(60%)-ZnO(40%) and TeO2(60%)-ZnO(20%)-BaO(20%) were prepared in the bulk form with following grinding into powders. The samples were X-ray irradiated. The created charge trapping centers were studied in both types of samples using electron paramagnetic resonance (EPR) spectroscopy. The O- defect and two types of F+ centers were discovered. One of the F+ center remained unchanged whereas the other one as well as the O- defect were affected by the presence of BaO. Moreover, photo-, radioand thermoluminescence (PL, RL, TL, respectively) methods were applied as well. The discovered charge trapping centers have been proven to influence luminescence properties as well - improving them in the TeO2(60%)ZnO(40%) and vice versa degrading them in the TeO2(60%)-ZnO(20%)-BaO(20%) glasses. The effect was even stronger in the grinded samples as compared to the bulk ones. The role of the BaO has been disclosed as supporting oxygen leakage from the host.

Automated summary

Charge trapping centers in two types of tellurite glasses were studied using X-ray irradiation and EPR spectroscopy. F+ centers and O- defect were discovered, and their behavior was affected by the presence of BaO. Additionally, the luminescence properties were studied using PL, RL, and TL methods, and the discovered charge trapping centers were found to influence the luminescence properties. The role of BaO was determined to support oxygen leakage.