Detalhes bibliográficos
| Ano de defesa: |
2020 |
| Autor(a) principal: |
Melo, Rosane Saraiva
 |
| Orientador(a): |
Franco Júnior, Adolfo
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| Banca de defesa: |
Franco Junior, Adolfo,
Oliveira, Cristhian Benedito de,
Alonso, Christian Gonçalves,
Araújo, Olacir Alves,
Valverde, Clodoaldo |
| Tipo de documento: |
Tese
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| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Federal de Goiás
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| Programa de Pós-Graduação: |
Programa de Pós-graduação em Química (IQ)
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| Departamento: |
Instituto de Química - IQ (RG)
|
| País: |
Brasil
|
| Palavras-chave em Português: |
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| Palavras-chave em Inglês: |
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| Área do conhecimento CNPq: |
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| Link de acesso: |
http://repositorio.bc.ufg.br/tede/handle/tede/11125
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Resumo: |
Ferrites have unique characteristics such as high permeability, high electrical resistivity, low losses due to eddy currents, among others, these being influenced by obtaining method. Due to these properties ferrites have been identified as an technological alternative to be used in magnectic and electronics materials and devices. Thus, the aim of this research is to synthesize cobalt and nickel ferrites Co1xNixFe2O4 (0.0<x<1.0) using two methods of synthesis: Hydrothermal and Forced Hydrolysis, and to evaluate the magnetic profile, as well as structural and morphological properties. Therefore, the samples were characterized by the techniques of X-ray diffractometry (XRD), Transmission Electron Microscopy, vibrational spectroscopy in the Infrared region and Vibrant Sample Magnetometry (VSM). The XRD results showed the formation of monophasic spinel nanometric structures of cubic arrangement for all samples, exhibiting variation of the structural parameters with the increasing in nickel concentration. The infrared spectroscopy analysis confirmed the formation of the spinel structures with the detected vibrational modes characteristic of tetrahedral and octahedral sites. Through microscopy we can observe the differences between the particles form obtained by Hidrotermal: spherical form x=0,0 and diamond form x=1,0; Forced Hydrolysis: almost spherical form for all samples. The particle sizes obtained by refinement showed a small difference being 17-80 nm and 5-9nm, Hydrothermal and Forced Hydrolysis respectively. Regarding the magnectic properties the samples exhibited totally different behaviors, being that samples obtained by Hydrothermal are ferrimagnetics with values of Ms and Hc between 70-48 emu/g e 1498-50 Oe (respectively) while samples obtained by Forced Hydrolysis showed superparamagnetism with saturation values 47-22 emu/g and coercivity and remanence are pratically null. |
