Caracterização estrutural dos compostos Ca2MnReO6 e Ca1,8Ce0,2MnReO6 através da técnica de absorção de raio X

• Autor(a) principal: Rodrigues, Erika Laurina Oliveira
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7456
• topic: Double peroviskite; X-ray diffraction (XRD); Scanning electron microscopy; Cerium doping; Peroviskitas duplas; XANES; EXAFS; Difração de raio X; Microscopia de varredura eletrônica; Dopagem com cério; Física; Raios X - Difração; Microscopia eletrônica; Supercondutores; 53

In this work will be presented a description about the synthesis methodsusing solid state reaction using the encapsulated quartz tube technique and a description about the morphogolical and strutural characteristics of the compounds Ca2MnReO6and Ca1,8Ce0,2MnReO6. The analysis of the diffraction patternusing Rietveld show us that the dopped sample doped with 5% cerium is monophasic to and it was also possible to note an expansion of the unit cell without changing the symmetry of the doped sample. The electron microscopy images showed a homogeneous size and shape of the particles in the sample. The measurements of X-ray absorption by synchrotron radiation at the edge K of Mnand the edge L3of Reshow that both elements have mixed valence in samples with and without doping , assuming a value for Re+7 in the doped , while the change was not observed value the valence of Mn.