Speaker
Abstract content <br> (Max 300 words)
Rare earth tantalates (MTaO4) with M = Gd, Y, La, are being extensively studied for possible applications in X-ray imaging systems and mercury free fluorescent lamps, and field emission display (FED) devices due to their high luminescence efficiency, physical and chemical stability, strong irradiation hardness and good X-ray absorption.1,2 In recent years, trivalent praseodymium (Pr3+) doped materials displaying red persistent luminescence are of considerable interest in the development of long persistent materials.3 In addition, the energy distribution of the defect levels within the forbidden region of these compounds is determined using thermoluminescence (TL) spectroscopy. Luminescent dynamics including fluorescence, phosphorescence, and thermoluminescence of Pr3+ in GdTaO4:Pr3+ is reported. X-ray diffraction (XRD) spectra indicated that GdTaO4:Pr3+ phosphor material is successfully prepared at 1200 °C using the solid state reaction method. Red and blue-green emissions were observed upon probing the materials with energetic photons using the DESY synchrotron radiation. A simplified energy transfer scheme explaining energy transfer from the TaO4 group to either Gd3+ states in the GdTaO4:Pr3+ system is presented. Afterglow measurements were carried out after UV irradiation at room temperature. The phosphorescence lifetime (τ) observed for GdTaO4:Pr3+ compound as a result of traps was 620 s. The depth of the trap levels was investigated from the TL data.
(1) Brixner, L. H.; Chen, H. Y. Chemical Etching Characteristics 1983, 130, 2435.
(2) Bo, L.; Kun, H.; Liu, X.; Gua, M.; Huanga, S.; Chen, N.; Qib, Z.; Zhang, G. Solid. Stat. Comm. 2007, 144, 484.
(3) Noto, L. L.; Pitale, S. S.; Terblans, J. J. Ntwaeaborwa O.M.; H.C. Swart, H.C. Physica B 2012, 407, 1517
Level for award<br> (Hons, MSc, <br> PhD)?
MSc
Apply to be<br> consider for a student <br> award (Yes / No)?
yes
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
Hendrik C. Swart, SwartHC@ufs.ac.za, University of Free State
