Preparação e cracterização de compósitos de CoFe2O4/ZrO2

• Autor(a) principal: Maciel, Sara Alves
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5738
• topic: Materiais magnéticos; Compósitos; Ferrita de cobalto; Óxido de zircônio; Nanopartículas; Magnetic materials; Composites; Cbaltferrites; Zircon oxide; Nanoparticles; CIENCIAS EXATAS E DA TERRA::QUIMICA

In this work, structural, morphological and magnetic properties of cobalt ferrite/zirconium oxide composites prepared via mechanical mixing of the powders were evaluated. Cobalt ferrite powders were obtained by coprecipitation, and some synthesis parameters were optimized, such as the speed of stirring , the concentration of base and metal solutions, in order to obtain stoichiometric ferrites (Fe3+/Co2+ = 2: 1) or near to it. Zirconium oxide powders were synthesized via sol-gel. The composites were analyzed by Atomic Absorption, Field Emission Scanning Electron Microscopy and Spectroscopy Dispersive Energy, Diffraction of X-rays, Infrared Spectroscopy and Vibranting Sample Magnetometry. It was observed the migration of cations between the ferrite and zirconia structures as a result of high diffusion between phases due to heat treatment. The analysis by Field Emission Scanning Electron Microscopy and Spectroscopy Dispersive Energy showed the different microstructures of aggregates present in the composites and the average diameter of the grains. The insertion of a magnetic phase on a non-magnetic matrix caused an increase in the saturation magnetization and the remanent magnetization, and decrease in coercivity as the cobalt ferrite content increases.