Results 171 to 180 of about 35,382 (205)

Maghemite in Icelandic basalts

Mineralogical Magazine, 1992
AbstractCurie temperatures indicating non-titaniferous magnetite are common in Icelandic basalts of all ages, especially Tertiary ones. Yet, microprobe analyses of such samples have shown high titanium in the magnetite. To resolve this paradox, and the mechanism at work, the magnetic mineral fraction of eight basalt samples with Js-T curves ...
S. Steinthorsson, Ö. Helgason, M. B. Madsen, C. Bender Koch, M. D. Bentzon, S. Mørup   +5 more
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Photoacoustic investigation of maghemite-based nanocomposite

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013
Photoacoustic spectroscopy was used to investigate magnetic nanocomposites incorporating nanosized maghemite particles into styrene-divinylbenzene copolymer template. Typical photoacoustic features were observed in bands C, S and L in the wavelength region of 300-1000 nm.
A F R, Rodriguez, M F S, Gilhermitti, F S E D V, Faria, R M, Cunha, J G, Santos, A C, Oliveira, M A, Morales, D, Rabelo, R B, Azevedo, P C, Morais   +9 more
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Magnetoviscous Effect in a Maghemite Ferrofluid

Journal of Nanoscience and Nanotechnology, 2011
An iron oxide ferrofluid with mean particle size of 10.6 nm was synthesized by co-precipitation. The nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, electron energy loss spectroscopy, and dynamic light scattering.
E, Ghasemi, A, Mirhabibi, M, Edrissi
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Photochemical reduction of nanocrystalline maghemite to magnetite

Nanoscale, 2021
We present a method for the photochemical conversion of the inverse spinel iron oxides in which the mixed-valent magnetite phase (Fe3O4) is accessed from the maghemite phase (γ-Fe2O3) via a stable, colloidal nanocrystal-to-nanocrystal transformation.
Hankyeol Jung, Alina M. Schimpf
openaire   +2 more sources

As(V) adsorption on maghemite nanoparticles

Journal of Hazardous Materials, 2009
In this study a novel adsorbent, maghemite nanoparticles (gamma-Fe(2)O(3)), is used for As(V) removal. Maghemite nanoparticles are an exceptional adsorbent material due to its magnetic properties and a good adsorption capacity. The aims of the study were to investigate the suitability of maghemite nanoparticles for As(V) adsorption and to compare ...
Tuutijarvi, Tanja, Lu, Jun, Sillanpaa, Mika, Chen, Guohua   +3 more
openaire   +3 more sources

Temperature dependence of the hyperfine parameters of maghemite and al-substituted maghemites

Physics and Chemistry of Minerals, 1995
Synthetic aluminum-substituted maghemite samples, γ-(Al y Fe1-y )2O3 with y=0, 0.032, 0.058, 0.084, 0.106 and 0.151 have been studied by Mossbauer spectroscopy at 8 K and in the range 80 K to 475 K at steps of 25 K. The spectra have been analysed as a superposition of two sextets composed of asymmetrical Lorentzians ...
G. M. da Costa, E. De Grave, L. H. Bowen, P. M. A. de Bakker, R. E. Vandenberghe   +4 more
openaire   +1 more source

Magnetic Maghemite Nanoparticles

1997
The chemical synthesis of maghemite (γFe3O4) magnetic nanoparticles and their complexation with dimercaptosuccinic acid (DMSA), yielding a solution of monocrystalline, monodomain, bare 7.5 nm particles (ferrofluid = FF) is described. The ferrofluid is stable in saline at neutral pH and enables binding of biological effectors to the particle core. Thus,
Avraham Halbreich, Jacky Roger, Jean-Noël Pons, Maria de Fatima Da Silva, Eric Hasmonay, Michel Roudier, Michel Boynard, Claude Sestier, Asmina Amri, Danielle Geldwerth, Bernard Fertil, Jean Claude Bacri, Domagoj Sabolovic’   +12 more
openaire   +1 more source

Variable-Temperature Mössbauer Spectroscopy of Nano-Sized Maghemite and Al-Substituted Maghemites

Clays and Clay Minerals, 1995
AbstractSynthetic aluminum-substituted maghemite samples, γ-(Fe1-xAlx)2O3, have been prepared by thermal decomposition of Al-lepidocrocite (γ-Fe1-xAlxOOH), with × = 0, 0.04, 0.06, 0.14 and 0.18. The particles are needle-shaped and the mean crystallite diameter along the [311] crystallographic direction was found to be between 2.0 and 5.0 nm.
G. M. Da Costa, E. De Grave, L. H. Bowen, P. M. A. De Barker, R. E. Vandenberghe   +4 more
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Rapid Synthesis and Characterization of Maghemite Nanoparticles

Journal of Nanoscience and Nanotechnology, 2008
Fe2O3–SiO2 nanocomposites were prepared by a sol–gel method using various evaporation surface to volume (S/V) ratios ranging from 0.03 to 0.2. The Fe2O3–SiO2 sols were gelated at various temperatures ranging from 50 °C to 70 °C, and subsequently they were calcined in air at 400 °C for 4 hours.
Tural, Bilsen, Oezenbas, Macit, Atalay, Selcuk, Volkan, Muervet   +3 more
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Magnetic properties of maghemite nanoparticles

Bulletin of the Russian Academy of Sciences: Physics, 2014
Magnetic particles of maghemite (spinel γ-Fe2O3) are synthesized by means of aerosol pyrolysis, making it possible to produce chemically uniform highly-dispersed single-phase materials. The magnetic properties of synthesized particles for temperatures ranging from helium temperature up to room temperature and higher are investigated using a SQUID ...
V. N. Nikiforov, A. E. Goldt, E. A. Gudilin, V. G. Sredin, V. Yu. Irhin   +4 more
openaire   +1 more source