Sínteses, caracterizações e estudo de propriedades físicas de nanocristais de ZnO dopados com íons metais de transição

• Ano de defesa: 2020
• Autor(a) principal: Batista, Elisson Andrade
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; Brasil; Programa de Pós-graduação em Física
• Palavras-chave em Português: Nanocristais; Nanocrystals; Óxido de zinco; Zinc oxide; Dopagem magnética; Magnetic doping; Precipitação química; Chemical precipitation; Solução aquosa; Aqueous solution; Espectroscopia Raman; Raman spectroscopy; Difração de raios-X; X-ray diffraction; Espectroscopia de absorção óptica; Optical absorption spectroscopy; Fluorescência; Fluorescence; Ressonância paramagnética eletrônica; Electronic paramagnetic resonance; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/28910; http://doi.org/10.14393/ufu.te.2019.2604

Zinc oxide (ZnO) is a semiconductor that has several interesting physical properties, which can be modified or improved depending on the transition metal (TM) incorporated into its crystalline structure. When doped, this material is called diluted magnetic semiconductor (DMS) and its properties are due to the strong sp-d exchange interaction between the charge carriers of the nanocrystals (NCs) and the unpaired electrons of the TM. In this work, we investigated the effect of both Mn and Co concentration on the physical properties of ZnO NCs, synthesized by the chemical precipitation method in aqueous solution. These properties were investigated by Raman spectroscopy, X-ray diffraction (XRD), optical absorption (OA) spectroscopy, fluorescence (FL), and electronic paramagnetic resonance (EPR). To investigate the ion incorporation in ZnO crystal structure, Rietveld refinements in the XRD data, crystalline field theory (CFT) in the OA spectra, and EPR results were used. The results showed that it is possible to control the NCs properties of ZnO, Zn1-xMnxO, Zn1-xMnxO/ZnMn2O4, and Zn1-xCoxO/ZnCo2O4 from the variation of the dopant concentration. We believe that these results may give rise to a great deal of interest in the scientific community, regarding the synthesis and processing of materials from the methodology adopted in this work, contributing to the understanding of the properties of semiconductor and/or semimagnetic nanostructures.