Influência da codopagem de terras-raras (Yb e Er) na luminescência do ZnAl2O4.

Abstract

Fine ceramic powders of aluminate of zinc doped with ions rare-earth (Yb3+:Er3+) they were prepared for combustion reaction with the objective of investigating the effect and the mechanism of emission upconversion for two different compositions. With this purpose they were made structural characterizations, microstructure and spectroscopy. The powders where synthesized with base in the concepts of the chemistry of the propellants. The results show the formation of the majority crystalline phase of ZnAl2O4:Yb:Er and traces of the secondary phases ZnO and Yb3Al5O12 and that the increase of the proportion Yb:Er favored to the rise of the secondary phases. All the compositions presented morphology formed by agglomerated constituted by fine particles. The superficial area increase with the rise of the Yb:Er proportion. Of the proportion of 5:1 in molls of Yb:Er a strong influence of the optic properties of the material host was verified. It was observed although the measures of optic spectroscopy revealed the predominance of the red color in relation to green, and that the emission intensity was influenced directly with the intensity infrared of the bomb. This result shows that ZnAl2O4 doped it can also become material interesting for luminescence obtained through upconversion of energy.