CONCENTRATION EFFECT OF THE EU3+ AND BI3+ IN THE PHOTOLUMINESCENCE PROPERTIES OF YVO4 MATRIX

Inorganic matrices have been extensively studied for several applications, mainly doped with lanthanoid ions presenting special spectroscopic properties. The radiation emission can be affected by several factors, such as; matrix, synthesis methodology, activating ions and sensitizers, and concentrations. Thus, in this work the matrix of yttrium vanadate doped with Eu3+ ions as activator and Bi3+ ions as sensitizer was prepared by the non-hydrolytic sol-gel methodology. Europium (III) and Bismuth (III) ions concentrations were varied in 1, 3 and 5% in mol with respect to the Y3+ ion and the samples were heat treated at 1000 °C. The X-ray diffraction analyzes showed a single phase of the yttrium vanadate matrix, indicating the non-influence of the dopant ions on the crystalline structure. The dopants concentrations presented influences on the spectroscopic properties of the emitting ion, the intensity parameters (Ω2 e Ω4), increased as a function of the increase of Bi3+ concentration, affecting the covalence of the bond and the rigidity of the system. The increase of Eu3+ concentration directly affected its environment, decreasing the symmetry and increasing the quantum efficiency. Finally, increasing the dopant ions promoted the decreasing the crystallite size.