Estudo da liga magnética "Alnico" sintetizado na forma de nanoplacas

• Ano de defesa: 2016
• Autor(a) principal: Ferreira, Rafael Franco
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Física; Programa de Pós-Graduação em Física; UEM; Maringá, PR; Centro de Ciências Exatas
• Palavras-chave em Português: Imãs permanentes, Alnico 2, Alnico 5 - Nanoplacas; Brasil.; Permanent magnet; Alnico 2; Alnico 5; Nanoplates; Brazil.; Ciências Exatas e da Terra; Física
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/2740

Nanostructured Alnico was prepared by a combination of dry and wet high-energy millings of a mixture of Fe, Co, Ni, Al and Cu powders. Rounded pellets were made by compacting the as-milled powder and then submitting it to thermal treatments at different temperatures. The as-milled and as-annealed samples were characterized by X-ray diffractometry, Mössbauer spectroscopy, scanning electron microscopy and magnetization techniques. The as-milled material revealed a face-centered cubic structure and nanoplate morphology, with a high aspect ratio and planar magnetization. The heat treatment transformed the crystalline structure mostly to body centered cubic, which is characteristic of Alnico at room temperature, with a microstructure made of nanoplates overlaid perpendicularly to the compaction direction. They revealed a coercive field and a saturation magnetization lower and higher, respectively, than that of alnico commercial samples .