Nickel ferrite on silica nanocomposites prepared by the sol–gel method

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.

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X-ray diffraction and Mossbauer studies on superparamagnetic nickel ferrite (NiFe2O4) obtained by the proteic sol–gel method

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2015.07.057 ◽

2015 ◽

Vol 163 ◽

pp. 402-406 ◽

Cited By ~ 16

Author(s):

N.A.S. Nogueira ◽

V.H.S. Utuni ◽

Y.C. Silva ◽

P.K. Kiyohara ◽

I.F. Vasconcelos ◽

...

Keyword(s):

Nickel Ferrite ◽

Sol Gel ◽

X Ray Diffraction ◽

Gel Method ◽

Mössbauer Studies ◽

X Ray ◽

Sol Gel Method

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Structural and morphologic characterization of zirconia–silica nanocomposites prepared by a modified sol–gel method

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2014.02.008 ◽

2014 ◽

Vol 401 ◽

pp. 462-468 ◽

Cited By ~ 5

Author(s):

Marcela Stoia ◽

Paul Barvinschi ◽

Floricica Barvinschi

Keyword(s):

Sol Gel ◽

Gel Method ◽

Sol Gel Method ◽

Silica Nanocomposites

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Characterisation of nickel–zinc ferrite/silica nanocomposites with low ferrite concentration obtained by an improved modified sol–gel method

Journal of Sol-Gel Science and Technology ◽

10.1007/s10971-010-2365-8 ◽

2010 ◽

Vol 58 (1) ◽

pp. 126-134 ◽

Cited By ~ 12

Author(s):

Marcela Stoia ◽

Costica Caizer ◽

Mircea Ştefănescu ◽

Paul Barvinschi ◽

Lucian Barbu-Tudoran

Keyword(s):

Zinc Ferrite ◽

Sol Gel ◽

Gel Method ◽

Sol Gel Method ◽

Silica Nanocomposites ◽

Nickel Zinc

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Investigation of magnetic properties of Al substituted nickel ferrite nanopowders, synthesized by the sol–gel method

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2011.06.026 ◽

2011 ◽

Vol 323 (23) ◽

pp. 2997-3000 ◽

Cited By ~ 13

Author(s):

M. Mozaffari ◽

Z. Abooalizadeh ◽

J. Amighian

Keyword(s):

Magnetic Properties ◽

Nickel Ferrite ◽

Sol Gel ◽

Gel Method ◽

Sol Gel Method

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Investigation and Structural Characterization of Nickel Ferrite Nanoparticles Produced by Proteic Sol-Gel Method Using Two Kinds of Organic Precursors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1574 ◽

2012 ◽

Vol 727-728 ◽

pp. 1574-1578

Author(s):

José Rafael C. Proveti ◽

Paulo Sergio da Silva Porto ◽

E.P. Muniz ◽

R.D. Pereira ◽

L.C.A. Gobbi

Keyword(s):

Crystallite Size ◽

Nickel Ferrite ◽

Strong Dependence ◽

Sol Gel ◽

Isothermal Treatment ◽

Metallic Oxide ◽

Organic Precursor ◽

Gel Method ◽

Sol Gel Method ◽

Organic Precursors

Metallic oxide materials with AB2O4 structure are very interesting for technological applications. Nickel ferrite (NiFe2O4), for example, attracts considerable attention due to its chemical stability and mechanical hardness. These characteristics make it a suitable material for magnetic and magneto-optical applications. The properties of NiFe2O4 have a strong dependence on the crystallite size and microstructure. Due to this dependence, it is necessary to develop effective methods that allow controlling these variables. The aim of this work is to investigate the effect of time, temperature of isothermal treatment and choice of organic precursor during the production of NiFe2O4 samples employing the proteic sol-gel method have on crystallite size and microstructure. Two kinds of organic precursors were used: coconut water and pectin extracted from aple peel. Temperatures of 873 and 1173 K; 2, 4, 6, 8, 24 and 30 hours of isothermal treatment were also used. The samples produced were analyzed employing X-ray Diffraction.

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