Production and characterization of luminescence proprieties of strontium aluminate compounds

Abstract

The main goal of the present work was to produce radiation-sensitive materials with phosphorescent properties to be tested in ceramic tiles. The investigated materials were strontium aluminate compounds co-doped with Eu2+ and Dy3+ ions. There are some evidence that the long lasting luminescence of the aluminates is due to the electronic transitions of the ion Eu2+, which are dependent on the host matrix. The presence of co-dopands has the function of promoting additional energy transfers that enhance the lifetime in the excited state. Strontium aluminate was produced in this work via proteic sol-gel route, in which the chloride salt precursors are dissolved in coconut water to form a sol. All the crystallization processes were monitored through X-ray diffraction (XRD) measurements. A mixture of the phases SrAl4O7 and SrAl2O4 was observed in samples produced under different calcinations temperatures. Optical absorption and photoluminescence (PL) measurements were performed in order to identify the wavelength corresponding to the maximum absorption and the emission spectrum of the samples doped with Eu2+ and Dy3+. Two absorption bands corresponding to both dopands were observed. Also, the PL measurements presented emission bands centered at about 591 nm, 613 nm and 681 nm, which were related to decay processes of both Dy3+ and Eu2+.