Surface-related properties of γ-Fe2O3 nanoparticles

Tronc, E.; Ezzir, A.; Cherkaoui, R.; Chanéac, Corinne; Noguès, M.; Kachkachi, Hamid; Fiorani, D.; Testa, A. M.; Grenèche, Jean‐Marc; Jolivet, Jean‐Pierre

doi:10.1016/s0304-8853(00)00369-3

Cited by 289 publications

(237 citation statements)

References 36 publications

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“…19 In Ref. 5, a speromagneticlike structure was observed for ␥-Fe 2 O 3 phosphate-coated nanoparticles with diameter of 3-10 nm as result for the interplay between surface anisotropy, exchange, and interparticle interactions.…”

Section: -15mentioning

confidence: 99%

Surface effects in the magnetic properties of crystalline 3 nm ferrite nanoparticles chemically synthesized

Lima

Biasi

Mansilla

et al. 2010

Journal of Applied Physics

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Ratchet effect of the domain wall by asymmetric magnetostatic potentials Appl. Phys. Lett. 99, 192512 (2011) Crystallization behavior and high temperature magnetic phase transitions of Nb-substituted FeCoSiBCu nanocomposites Appl. Phys. Lett. 99, 192506 (2011) Room temperature magnetoelectric memory cell using stress-mediated magnetoelastic switching in nanostructured multilayers Appl. Phys. Lett. 99, 192507 (2011) Current-induced domain wall motion in permalloy nanowires with a rectangular cross-section J. Appl. Phys. 110, 093913 (2011) Correlation between symmetry-selective transport and spin-dependent resonant tunneling in fully epitaxial Cr/ultrathin-Fe/MgO/Fe(001) magnetic tunnel junctions Appl. Phys. Lett. 99, 182508 (2011) Additional information on J. Appl. Phys. We have systematically studied the magnetic properties of ferrite nanoparticles with 3, 7, and 11 nm of diameter with very narrow grain size distributions. Samples were prepared by the thermal decomposition of Fe͑acac͒ 3 in the presence of surfactants giving nanoparticles covered by oleic acid. High resolution transmission electron microscopy ͑HRTEM͒ images and XRD diffraction patterns confirms that all samples are composed by crystalline nanoparticles with the spinel structure expected for the iron ferrite. ac and dc magnetization measurements, as well in-field Mössbauer spectroscopy, indicate that the magnetic properties of nanoparticles with 11 and 7 nm are close to those expected for a monodomain, presenting large M S ͑close to the magnetite bulk͒. Despite the crystalline structure observed in HRTEM images, the nanoparticles with 3 nm are composed by a magnetically ordered region ͑core͒ and a surface region that presents a different magnetic order and it contains about 66% of Fe atoms. The high saturation and irreversibility fields in the M͑H͒ loops of the particles with 3 nm together with the misalignment at 120 kOe in the in-field Mössbauer spectrum of surface component indicate a high surface anisotropy for the surface atoms, which is not observed for the core. For T Ͻ 10 K, we observe an increase in the susceptibility and of the magnetization for former sample, indicating that surface moments tend to align with applied field increasing the magnetic core size.

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Section: -15mentioning

confidence: 99%

Surface effects in the magnetic properties of crystalline 3 nm ferrite nanoparticles chemically synthesized

Lima

Biasi

Mansilla

et al. 2010

Journal of Applied Physics

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“…In panel (b) the Mössbauer spectra are collected of the particles obtained from the mixture of Fe(acac) 3 and Fe(acac) 2 in the stechiometric ratio 2:1 what should lead to pure magnetite. In panels (c) and (d) the spectra of core-shell type of the particles are shown: magnetite on maghemite and maghemite on magnetite, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…2b four samples of pure magnetite were tested with different concentration of constituents taken in second step of the synthesis. Here the total amount of Fe(acac) 3 and Fe(acac) 2 is varied between 2 and 8 mmol in steps of 2 mmol. The relative molar ratio between Fe 3+ and Fe 2+ compounds were kept 2:1 as is typical for stoichiometric magnetite.…”

Section: Resultsmentioning

confidence: 99%

“…Next, the following growth on seeds was made with the concentration of Fe(acac) 3 complex or both Fe(acac) 3 and Fe(acac) 2 complexes ranged from 1 to 8 mmol [7].…”

Section: Methodsmentioning

confidence: 99%

“…Each step can lead to a different composition of the layer and in this way the particles can posses quite exotic structures with fine tunable properties. Each surface modification causes changes of magnetic properties nanoparticles [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Mössbauer Studies of Core-Shell Nanoparticles.

et al. 2011

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The ferrite magnetic nanoparticles with core-shell structures were obtained in two step preparation process. The Mössbauer spectra obtained for particles of pure maghemite or magnetite and two layered core-shell one the magnetite on maghemite and maghemite on magnetite are very different from each other. The presented results show that interparticle and intraparticle interaction plays important role in overall magnetic properties as well.

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Superparamagnetic Particles

Mørup

Hansen

2007

Handbook of Magnetism and Advanced Magnetic Materials

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The magnetic properties of nanoparticles are reviewed with special emphasis on magnetic relaxation phenomena. After an introduction to superparamagnetic relaxation phenomena, we give a brief introduction to synthesis of nanoparticles and how they can be characterized by standard techniques such as X‐ray diffraction, electron microscopy, and other techniques. We then describe how one can study magnetic relaxation phenomena in noninteracting nanoparticles by different experimental techniques such as DC and AC magnetization measurements, Mössbauer spectroscopy, and neutron scattering. Subsequently, the influence of interparticle interactions on the relaxation is discussed, and it is shown that both magnetic dipole and exchange interactions between nanoparticles can have a significant influence on the relaxation phenomena. Finally, we discuss the magnetic structure in nanoparticles and how spin canting and transverse relaxation can influence the magnetic properties of nanoparticles.

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Surface-related properties of γ-Fe2O3 nanoparticles

Cited by 289 publications

References 36 publications

Surface effects in the magnetic properties of crystalline 3 nm ferrite nanoparticles chemically synthesized

Surface effects in the magnetic properties of crystalline 3 nm ferrite nanoparticles chemically synthesized

Mössbauer Studies of Core-Shell Nanoparticles.

Superparamagnetic Particles

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