Impact of europium concentration on thermal and absorption features of amorphous tellurite media

• Main Authors: Hamzah, Khaidzir, Suffian, Ahmad Farhan, Ghoshal, Sib Krishna
• Format: Conference or Workshop Item
• Language: English
• Published: 2015
• Subjects: QD Chemistry
• Online Access: http://eprints.utm.my/id/eprint/63446/1/SibKrishnaGhoshal2015_ImpactofEuropiumConcentrationonThermalandAbsorptionFeatures.pdf; http://eprints.utm.my/id/eprint/63446/; http://www.utm.my/ispc2015/

Improving the structural and optical properties of tellurite glasses via optimized doping of rare earth ions is an outstanding issue in materials science. Tellurite glasses doped with trivalent europium (Eu3+) are successfully prepared using conventional melt quenching technique. Glasses with chemical composition of (80-x)TeO2-10PbO-10ZnO-(x)Eu2O3 where 0 ≤ x ≤ 2.0 mol% are obtained. The influence of Eu3+ ions concentration on the thermal and absorption properties of the synthesized glasses is investigated using Differential Thermal Analyzer (DTA) and UV-VIS Spectroscopy. DTA curves in the temperature range of 50-1000 °C at a heating rate of 10 °C/min are used to determine the temperature of glass transition, crystallization, melting and in turn the thermal stability. DTA revealed that the increase in the Eu3+ contents improved the thermal stability. This observation is attributed to the alteration of the glass network structure via the creation of non-bridging oxygen. The room temperature absorption spectra recorded in the spectral region of 200 – 2000 nm exhibited three absorption peaks corresponding to 7F0 → 5D0, 7F0 → 5D1 and 7F0 → 5D2 transitions. The absorption intensity is found to be enhanced up to certain concentration of Eu3+ ions and then quenched. This is ascribed to the change in glass network structure and formation of defects through the cleavage of weak bonds and reduction in covalence states.