Produção pelo método do acetato para caracterização por fotoluminescência do composto LiZnNbO4:Co2+

Abstract

This work addresses the production and analysis of the optical and crystallographical properties of the LiZnNbO4 advanced ceramic using Co2+ as substitutional impurity in the samples, at concentration of 1,0%, 5,0% and 50,0%. The samples were synthesized by chemical method (wet chemical) and the analysis of crystal structure and the verification of the formed phases were realized through of X-ray diffraction. Photoluminescence measurements were realized at room temperature and atmospheric pressure, with an excitation wavelength of 600 nm. Emission spectra consisted of broadbands, between 650 nm and 780 nm, with a barycenter at 729 nm (1.0%) and 733 nm (5.0%), in the red-infrared region, with the most intense emission observed in the sample with 1.0% of Co2+. Excitation spectra were monitored in the 720 nm emission of the 1.0% and 5.0% LiZnNbO4:Co2+ samples and the calculated values of the Racah and crystal field parameters using experimental data indicate that the observed transitions are characteristic of the Co2+ ion in tetrahedral symmetry. The 50.0% sample did not show luminescence. The wide emission bands observed in the near-infrared red region indicate that materials with concentrations of 1.0% and 5.0% of Co2+ are promising to be used as tunable radiation sources at room temperature.