Effect of solvent, host precursor, dopant concentration and crystallite size on the fluorescence properties of Eu(III) doped yttria

A systematic spectroscopic study of Eu3+ doped yttria powder phosphors are reported. Fluorescence study of this system has been investigated under the different solvent systems, e.g. ethanol and water. In this study, the effect of the precursor of yttria, e.g. acetate, nitrate and chloride, on the fluorescence behaviour of Eu3+ have been observed in particular. Attention was paid to their effect on the emission intensity of the D-5(0)-->F-7(2) transition which is characteristic of the 'red fluorescence' of the Eu3+ ion. Results show that the CH3COO(-) ion has a tremendous effect on the enhancement of emission intensity, greater than NO3- and Cl- ions. The Fourier transformed infrared (FTIR) spectroscopy was used for chemical and structural analysis. It has also been stated that the concentration quenching of dopant was more pronounced in the powders derived from yttrium chloride than from yttria precursor. In the case of Y(CH3COO)(3) as a precursor, the concentration quenching was totally absent and emission intensity increased with an increase in the concentration of dopant. This paper also includes some interesting results on the effect of modifiers, which are a mixture of Tween-80 with epsilon-caprolactum/beta-alanine/emulsogen-OG, on the D-5(0)-->F-7(2) transition of Eu3+ doped yttria in terms of crystallite size in brief. (C) 1998 Elsevier Science B.V.