Photoluminescence Characteristics of Pure and Dy-Doped ZnNb2O6 Nanoparticles Prepared by a Combustion Method

Pure and Dy-doped ZnNb 2 O 6 nanoparticles have been prepared by a sol−gel combustion method using citric acid as a fuel and complexing agent and nitrates as oxidants at a relatively low temperature as compared to solid-state reaction methods. X-ray diffraction patterns of the pure ZnNb 2 O 6 samples show that the ZnNb 2 O 6 nanoparticles exhibit an orthorhombic phase. Photoluminescence (PL) properties of all the undoped and Dy-doped samples are studied in detail. For the pure ZnNb 2 O 6 samples, a strong blue emission band centered at 445 nm and two weak emission bands centered at 525 and 625 nm, respectively, can be observed. For Dy-doped ZnNb 2 O 6 samples, the luminescence of Dy 3+ is observed with the host blue emission remaining and the host emission intensity varying with the Dy-doping concentrations. This novel PL characteristic of the doped samples may be attributed to the energy transfer between Dy 3+ and niobate groups (NbO 6 ).