Synthesis and Investigation of La,Ca -Doped EuVO4 Nanoparticles with Enhanced Excitation by Near Violet Light

The paper reports experimental results on features of crystal structure and luminescent properties of the Eu1-xCayVO4 nanoparticles synthesized for the first time. The Eu1-xCaxVO4 compounds with x=0, 0.05, 0.1, 0.15, and 0.20 are prepared by aqueous nitrate-citrate sol-gel synthesis. The obtained samples are characterized by XRD analysis. The Eu1-xCaxVO4 samples are crystallized in tetragonal structure. Phase composition of the sample depends on the x value. Increasing concentrations of the calcium ions leads to formation of the EuVO4 and CaV2O6 phases' mixture. Luminescence properties of the synthesized Eu1-xCaxVO4 nanoparticles are considered in comparison with properties of the La1-x-yEuyCaxVO4 nanoparticles. Formation of two types of emission centers and arising of additional excitation band near 400nm are observed for the both compositions. It is shown that second types of the emission centers have different structure and spectral characteristics for the Eu1-xCaxVO4 and La1-x-yEuyCaxVO4 nanoparticles, whereas the 400nm excitation band has the same origin for the both compositions.