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Previous issue date: 2014-05-27 / Universidade Federal do Rio Grande do Norte / In this work we obtain nickel ferrite by the combustion synthesis method whcih
involves synthesising in an oven at temperatures of 750oC, 950oC and 125oC.
The precursors oxidizing used were nickel nitrate, ferric as an oxidizing and reducing
urea (fuel). After obtaining the mixture, the product was deagglomerated
and past through a 270 mesh sieve. To assess the structure, morphology, particle
size, magnetic and electrical properties of nanoparticles obtained the samples were
sintered and characterized by x-ray distraction (XRD), x-ray fluorescence spectroscopy
(FRX); scanning electron microscopy (SEM), energy dispersive spectroscopy
(EDS), vibrating sample magnetometer (MAV ) and electrical permittivity. The results
indicated the majority of phase inverse spinel ferrite and Hematite secondary
phase nickel and nickel oxide. Through the intensity of the distraction, the average
size of the crystallization peaks were half-height width which was calculated using
the Scherrer equation. From observing the peaks of all the reflections, it appears
that samples are crystal clear with the formation of nanoparticles. Morphologically,
the nanoferritas sintered nickel pellet formation was observed with three systems of
particle size below 100mn, which favored the formation of soft pellets. The average
size of the grains in their micrometric scale. FRX and EDS showed qualitatively
the presence of iron elements nickel and oxygen, where through quantitative data
we can observe the presence of the secondary phase. The magnetic properties and
the saturation magnetization and the coercive field are in accordance with the nickel,
ferrite where the curve of hysteresis has aspects of a soft material. Dielectric
constant values are below 10 and low tangent loss / Este trabalho descreve a obten??o de ferrita de n?quel pelo m?todo de s?ntese
de combust?o, seguida pela sinteriza??o em forno, ?s temperatura de 750oC, 950oC
e 1250oC. Os precursores oxidantes utilizados foram: nitratos de n?quel e ferro III
como redutor, foi usada a ur?ia (combust?vel). Depois da obten??o do p?s-misturas,
o produto foi desaglomerado e passado em uma peneira de mesch 270. A estrutura, a
morfologia, o tamanho das part?culas e as propriedades magn?ticas e el?tricas das nanopart
?culas obtidas das amostras p?s sinterizadas foram caracterizadas por difra??o
de raios-X (DRX), espectroscopia de uoresc?ncia de raios-X (FRX), microscopia
eletr?nica de varredura (MEV ), espectroscopia de energia dispersiva (EDS), magnet
?metro de amostra vibrante (MAV ) e an?lise el?trica. Os resultados indicaram
a fase majorit?ria do espin?lio inverso ferrita de n?quel e a fase secund?ria de hematita
e ?xido de n?quel. Atrav?s da intensidade dos picos de difra??o de raios-X e
da largura de meia altura no espectro, foi calculado o tamanho m?dio do cristalito
pela equa??o Scherrer, observando-se os picos de todas as re ex?es, veri cando a
cristalinidade das amostras, e com forma??o de nanopart?culas. Morfologicamente,
para as nanoferritas de n?quel sinterizadas, observou-se a forma??o de aglomerados
moles nos tr?s sistemas com part?culas de tamanho inferior a 100nm. O tamanho
m?dio dos gr?os est? em escala microm?trica. Os espectros de FRX e EDS mostraram
qualitativamente a presen?a dos elementos ferro, n?quel e oxig?nio. Atrav?s
dos dados quantitativos, pode-se observar a presen?a da fase secund?ria. As propriedades
magn?ticas, como a magnetiza??o de satura??o e o campo coercitivo, est?o
de acordo com a ferrita de n?quel, em que a curva de histerese tem aspectos de um
material mole. Os valores de constante diel?trica est?o abaixo de 10 e baixa tangente
de perdas.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/18676 |
| Date | 27 May 2014 |
| Creators | Santos, Paulo Roberto Cunha dos |
| Contributors | CPF:16225422404, http://lattes.cnpq.br/3511004608337461, Oliveira, Jo?o Bosco Lucena de, CPF:19127537404, http://lattes.cnpq.br/1360004695124740, Moura, Maria de F?tima Vit?ria de, CPF:31482015404, http://lattes.cnpq.br/2959800336802498, Bueno, Aline Carvalho, CPF:05249192670, http://lattes.cnpq.br/8697236903588512, Silva, Ademir Oliveira da |
| 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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