Tuning of luminescent properties of Zn1-xMgAl10O17:Eu-x nano phosphor

The Zn1-xMgAl10O17:Eu-x(2+) (x = 0.01-0.4) nano phosphors were prepared successfully using the combustion route by employing urea as a fuel. The structural, microstructural, thermal, optical and luminescent properties were measured on the samples. The nano phosphors were found to be of surface area (similar to 13.92 m(2)/g) and insulators of the band gap (similar to 5.24eV). Photoluminescence properties on the samples were characterized by excitation (lambda(ex) . = 340 nm) and emission (lambda(em) = 440 nm) spectra. The phosphors showed strong blue luminescence (440 nm-460 nm) as well as showed weak luminescence in 577 nm, 589 nm, 596 nm, and 615 nm in the orange-red region, which are attributed to 4f(6)5 d(1)-> 4f(7) and D-5(0)-> F-7(j) (j = 0, 1,...) transitions of the Eu (II) and Eu (III) ions respectively. The tuning of this blue luminescent properties as compared to the earlier reported red luminescence has been achieved. Thermo-luminescence glow curve recorded under 10-minute dose of UV (254 nm) radiation have been used to calculate the kinetic parameters and the activation energy of the nano phosphors by using the Chens-equation. The TL emission spectra of the Zn0.99MgAl10O17:Eu(0.01 )phosphor showed the characteristic Eu2+ emission peaks -450 nm (blue) originating from the transitions 4f(6)5 d(1) -> 4f(7). The possible mechanism of the PL and TL of blue light emitting phosphor are also discussed. (C) 2018 Elsevier B.V. All rights reserved.