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Previous issue date: 2013-07-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Magnetic ceramics have been widely investigated, especially with respect to intrinsic and
extrinsic characteristics of these materials. Among the magnetic ceramic materials of
technological interest, there are the ferrites. On the other hand, the thermal treatment of
ceramic materials by microwave energy has offered various advantages such as: optimization
of production processes, high heat control, low consumption of time and energy among
others. In this work were synthesized powders of Ni-Zn ferrite with compositions Ni1-
xZnxFe2O4 (0.25 ≤ x ≤ 0.75 mols) by the polymeric precursor route in two heat treatment
conditions, conventional oven and microwave energy at 500, 650, 800 and 950?C and its
structural, and morphological imaging. The materials were characterized by thermal analysis
(TG/ DSC), X-ray diffraction (XRD), absorption spectroscopy in the infrared (FTIR),
scanning electron microscopy (SEM), X-ray spectroscopy and energy dispersive (EDS) and
vibrating sample magnetometry (VSM). The results of X-ray diffraction confirmed the
formation of ferrite with spinel-type cubic structure. The extrinsic characteristics of the
powders obtained by microwave calcination and influence significantly the magnetic behavior
of ferrites, showing particles ferrimagn?ticas characterized as soft magnetic materials (soft), is
of great technological interest. The results obtained led the potential application of microwave
energy for calcining powders of Ni-Zn ferrite / Cer?micas magn?ticas t?m sido amplamente investigadas, principalmente com rela??o
as caracter?sticas intr?nsecas e extr?nsecas destes materiais. Dentre os materiais cer?micos
magn?ticos de interesse tecnol?gico, destacam-se as ferritas. Por outro lado, o tratamento
t?rmico de materiais cer?micos por energia de microondas tem oferecido diversas vantagens,
tais como: otimiza??o dos processos de obten??o, alto controle de aquecimento, menor
consumo de tempo e energia entre outras. Neste trabalho, foram sintetizados p?s de ferritas
Ni-Zn com composi??es Ni1-xZnxFe2O4 (0,25 ≤ x ≤ 0,75 mols) pela rota dos precursores
polim?ricos em duas condi??es de tratamento t?rmico, em forno convencional e por energia
de microondas a 500, 650, 800 e 950?C, e sua caracteriza??o estrutural, morfol?gica e
magn?tica. Os materiais obtidos foram caracterizados por an?lises t?rmicas (TG/DSC),
difra??o de raios x (DRX), espectroscopia de absor??o na regi?o do infravermelho (FTIR),
microscopia eletr?nica de varredura (MEV), espectroscopia de raios X por dispers?o de
energia (EDS) e magnetometria de amostra vibrante (VSM). Os resultados da difra??o de
raios X confirmaram a forma??o da ferrita com estrutura c?bica do tipo espin?lio. As
caracter?sticas extr?nsecas dos p?s obtidos e a calcina??o por microondas influenciaram de
forma significativa o comportamento magn?tico das ferritas, apresentando part?culas
ferrimagn?ticas, caracterizadas como materiais magn?ticos moles (macias), sendo de grande
interesse tecnol?gico. Os resultados obtidos induziram o potencial de aplica??o de energia de
microondas para a calcina??o de p?s de ferritas Ni-Zn
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12816 |
| Date | 04 July 2013 |
| Creators | Assis, Raimison Bezerra de |
| Contributors | CPF:24779953839, http://lattes.cnpq.br/9918299069511517, Paskocimas, Carlos Alberto, CPF:06296687877, http://lattes.cnpq.br/2365059843175411, Timoteo J?nior, Jos? Fl?vio, CPF:01077102429, http://lattes.cnpq.br/2896156171155001, Delmonte, Mauricio Roberto Bomio, CPF:27816279841, http://lattes.cnpq.br/9558299312183852, Motta, Fabiana Villela da |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncia e Engenharia de Materiais, UFRN, BR, Processamento de Materiais a partir do P?; Pol?meros e Comp?sitos; Processamento de Materiais a part |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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