Síntese do Mg2SnO4:Co2+ com concentrações de 0,003% a 100% e estudo de suas propriedades ópticas e microestruturais

Abstract

In this thesis, we present the synthesis and characterization of ceramic samples of Mg2SnO4 (magnesium stannate) with concentrations of Co2+ ranging from 0.003% to 100%. These samples were synthesized using the acetate method with ultra-pure reagents of MgO, SnO2, and CoCO3. The main compounds Mg2SnO4 and Co2SnO4 were identified, and some residual oxides MgO and SnO2 were identified through X-ray diffraction and structurally characterized by the Rietveld method, analyzing the volume of the unit cell, the size of the crystallite, the microdeformation, the displacement density, and the porosity of the sample. The optical characterization was carried out at room temperature and atmospheric pressure through photoluminescence, where the favorable concentration for the luminescence of this compound and the critical distance between Co2+ emitting centers were identified. The Crystal Field parameters, Dq, and Racah, B and C, for each concentration that presented luminescence and the type of optical transition were determined by the emission, excitation, and lifetime spectra.