Optical and structural properties of Ni2+-doped magnesium gallate polycrystalline samples

We present the photoluminescence and photoacoustic data at room temperature of the Mg(1-x)Ni(x)Ga2O4 with x = 0.001, 0.005 and 0.01. The samples were prepared by solid state reaction, and the quality control was done by X-ray diffraction and SEM (scanning electron microscope) images. Rietveld refinements showed the MgGa2O4 formation and the appearance of some quantity of Ga2O3 as secondary phase with increasing doping level. These results were confirmed through SEM. The spectra of emission exhibit broad bands in green-yellow and red-infrared limit regions, characteristics of the octahedral Ni2+. Photoacoustic spectra show transitions associated to Ni2+ ions in octahedral and tetrahedral sites. (C) 2012 Elsevier B. V. All rights reserved.