文摘
We used the non-hydrolytic sol-gel route to synthesize YVO4 crystalline phases doped with europium III ion. We heat-treated the samples at 600, 800, and 1000 掳C and characterized the materials by thermal analysis, X-ray diffraction, small-angle X-ray scattering, and photoluminescence. Larger weight loss occurred until 500 掳C, ascribed to removal of residual precursor molecules. X-ray diffraction patterns evidenced YVO4 phase formation at 600 掳C. The crystallite size depended on the heat treatment temperature. SAXS showed that the nature of the system interfaces changed as a function of the thermal treatment. The excitation spectra of the samples displayed the charge transfer band. The photoluminescence data revealed the characteristic transition bands arising from the 5D0鈫?sup>5FJ (J=0, 1, 2, 3, and 4) manifolds under maximum excitation at the charge transfer band and the 5L6 level of the Eu3+ ion. The 5D0鈫?sup>7F2 transition dominated the emission spectra, indicating that the Eu3+ ion occupies a site without inversion center. The lifetime and quantum efficiency values were about 0.70 ms and 50%, respectively, corroborating literature results.
