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Previous issue date: 2010-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Were synthesized ferrites of NiZn on systems Ni0,5Zn0,5Fe2O4, the
precursors citrate method. The decomposition of the precursors was studied by
thermogravimetric analysis and spectroscopy in the infrared region, the
temperature of 350?C/3h. The evolution of the phases formed after calcinations
at 350?C/3h, 600, 1000 and 1100?C/2h was accompanied by X-ray diffraction
using the Rietveld refinement method for better identification os structures
formed. Was observed for samples calcined at different temperatures increased
crystallinity with increasing calcination temperature, being observed for the
samples calcined at 900 and 1100 ? C/2h was the precipitation of a secondary
phase, the phase hematite. The ferrocarbonila of industrial origin was analyzed
by X-ray diffraction and Rietveld for the identification of its structure. The
carbonyl iron was added NiZn ferrite calcined at 350?C/3h, 600, 900, 1000 and
1100?C/2h to the formation of hybrid mixtures. They were then analyzed by Xray
diffraction and Rietveld. The NiZn ferrite and ferrocarbonila as well as the
hybrid mixtures were subjected to analysis of scanning electron microscopy,
magnetic measurements and reflectivity. The magnetic measurements indicated
that the ferrite, the ferrocarbonila, as well as hybrid mixtures showed
characteristics of soft magnetic material. The addition of ferrocarbonila in all
compositions showed an increase in the results of magnetic measurements and
reflectivity. Best result was observed in the increase of the magnetization for the
hybrid mixture of Ferrocarbonila / ferrite of NiZn calcined at 600?C/2h. The
mixture Ferrocarbonila / ferrite calcined 1000?C/2h presented better absorption
of electromagnetic radiation in the microwave / Foram sintetizadas ferritas de NiZn no sistema Ni0,5Zn0,5Fe2O4, pelo
m?todo dos citratos precursores. A decomposi??o dos precursores foi estudada
por an?lise termogravim?trica e espectroscopia na regi?o do infravermelho na
temperatura de 350?C/3h. A evolu??o das fases formadas ap?s calcina??es a
350?C/3h, 600, 1000 e 1100?C/2h foi acompanhada por difra??o de raios X
utilizando o refinamento de Rietveld para melhor identifica??o das estruturas
formadas. Foi observado para as amostras calcinadas em diferentes
temperaturas o aumento da cristalinidade com o aumento da temperatura de
calcina??o, sendo verificado que para as amostras calcinadas a 900 e
1100?C/2h ocorreu a precipita??o de uma fase secund?ria, a fase hematita. A
ferrocarbonila de proced?ncia industrial foi analisada por Difra??o de raios X e
por Rietveld para a identifica??o de sua estrutura. A ferrocarbonila foi
adicionada ? ferrita de NiZn calcinada a 350?C/3h, 600, 1000 e 1100?C/2h para
a forma??o das misturas h?bridas. Em seguida foram analisadas por difra??o
de raios X e por Rietveld. A ferrita de NiZn, a ferrocarbonila, assim como as
misturas h?bridas foram submetidas ? an?lises de Microscopia Eletr?nica de
Varredura, medidas magn?ticas e refletividade. As medidas magn?ticas
indicaram que a ferrita, a ferrocarbonila, como tamb?m as misturas h?bridas
apresentaram caracter?sticas de material magn?tico macios. A adi??o de
ferrocarbonila em todas as composi??es indicou um aumento nos resultados de
medidas magn?ticas e de refletividade. Foi verificado melhor resultado no
aumento da magnetiza??o para a mistura h?brida de Ferrocarbonila/ferrita de
NiZn calcinada 600?C/2h. A mistura Ferrocarbonila/ferrita calcinada 1000?C/2h
apresentou melhor resultado absor??o da radia??o eletromagn?tica na faixa de
microondas em rela??o ?s outras misturas
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17652 |
| Date | 31 August 2010 |
| Creators | Rodrigues, Manuella Karla da Cruz |
| Contributors | CPF:02168290890, http://lattes.cnpq.br/9213856023536973, Oliveira, Jo?o Bosco Lucena de, CPF:19127537404, http://lattes.cnpq.br/1360004695124740, Dantas, Josiv?nia Marisa, CPF:87478501400, http://lattes.cnpq.br/6685565063970044, Andrade J?nior, Tarc?sio El?i de, CPF:78880129472, http://lattes.cnpq.br/2632090211894151, Nasar, Ricardo Silveira |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| 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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