Estudo da Incorporação de Mn à matriz de ZnO: Preparação e Caracterização Estrutural

Abstract

In this dissertation we present the studies related to the preparation and the structural characterization of Mn-doped ZnO samples (Zn1-xMnxO) in the atomic concentration of x = 0.06; 0.08; 0.10; 0.12; 0.14, 0.16, 0.18, 0.20 e 0.22. Special attention is devoted to the substitutional incorporation of the Mn atoms into the wurtzite ZnO lattice. The samples were prepared via standard solid state reaction method and characterized by using the techniques: X-ray diffraction and Rietveld refinement, Raman scattering spectroscopy, scanning electron microscopy and energy dispersive spectroscopy, X-ray absorption and diffuse reflectance spectroscopy. The obtained results confirm the incorporation of the Mn atoms up to the limit of ~ 21 at.%. The analyses performed via diffuse reflectance spectroscopy reveal a decrease of the energy band gap from 3.4 eV for the undoped ZnO to 2.15 eV for the Mn-doped ZnO samples. The overall results show that the prepared materials have potential applicability in the areas of photocatalysis, thermoelectricity (energy harvesting) and spintronics.