Magnetic properties of nanometric nickel particles

Broto, J. M.; Ousset, J.C.; Rakoto, H.; Askénazy, S.; Dufor, Ch.; Brieu, M.; Mauret, P.

doi:10.1016/0038-1098(93)90450-2

Cited by 9 publications

(12 citation statements)

References 9 publications

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“…1, based on a modification of Gen's levitationjet method. 19,23,[52][53][54] In this technique, a nickel wire is suspended inside a thin quartz tube (inner diameter -14 mm), heated up to melting and vaporization by the action of an electromagnetic field generated by a counter-current inductor powered by an industrial high frequency (HF) generator. This forms a liquid Ni droplet at the end of the wire.…”

Section: Methodsmentioning

confidence: 99%

“…15 Although bulk metal Ni is ferromagnetic and NiO is antiferromagnetic, when their characteristic length scales are within a few nanometres, noticeable changes in their magnetic properties take place. 4,[16][17][18][19][20][21][22][23] Below approximately 17 nm, 24 ferromagnetic Ni nanoparticles are expected to enter a superparamagnetic regime as the thermal energy becomes dominant, hence randomizing the magnetic moments over a more or less wide range of temperatures greatly influenced by the particular size distribution. Both finite size and surface effects in very small NiO nanoparticles lead to a high magnetic moment and anisotropy.…”

Section: Introductionmentioning

confidence: 99%

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Electric field-assisted levitation-jet aerosol synthesis of Ni/NiO nanoparticles

et al. 2012

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Ni/NiO powdered nanoparticles with average sizes 10-30 nm were prepared by a levitation-jet method involving the condensation of Ni metal vapour in a mixture of helium with various amounts of air or oxygen. The process was undertaken with the application of a DC electric field up to 6.5 kV cm À1 . The particles were characterized by X-Ray diffraction, transmission electron microscopy, BET adsorption and vibrating sample magnetometry. It was found that the intensity of the applied electric field and partial oxygen pressure correlated with the main structural and magnetic parameters of the nanoparticles, such as average particle size, residual ratio of nickel, coercivity and maximum magnetisation. The specific surface area of the particles correlated with the magnitude of the external electric field. Room-temperature hysteresis loops of weakly oxidized nanoparticles show ferromagnetic-like behaviour, whereas the strongly oxidized ones exhibit a low-field ferromagnetic feature superimposed to a paramagnetic signal, regardless of the particle size. Magnetic measurements allowed for the estimation of the residual metal Ni content in the powdered nanoparticles, which can be as low as 0.04 at.% depending on oxygen partial pressure and external electric field strength.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electric field-assisted levitation-jet aerosol synthesis of Ni/NiO nanoparticles

et al. 2012

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“…5͔͒ of the dimer, as well as studies of the variation of the ionization potential 2,6 ͑IP͒ and the magnetic moments [7][8][9] with the size of the cluster. Several experiments 7,[10][11][12][13][14][15] have shown that the chemical and physical properties of clusters such as ionization potential, magnetic moment per atom, and attachment energies change with the size of the cluster, converging eventually to bulklike behavior. 16 The rate of convergence depends on the property that quantitative convergence often requiring tens, hundreds, or even more atoms.…”

Section: Introductionmentioning

confidence: 99%

Structure and properties of cobalt clusters up to the tetramer: A density-functional study

et al. 1997

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All-electron calculations have been performed on cobalt clusters up to the tetramer using the local and generalized gradient correction spin density formalisms. These clusters present an abundance of low-lying states. In the case of Co 4 , we have found that two and three-dimensional structures are energetically very close. Symmetric structures exhibit high degeneracy. Jahn-Teller deformations have hence been investigated and have been found to play an important role in such transition-metal clusters. General trends in the magnetic moment per atom and in the attachment energy have been elucidated.

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“…Small transition metal clusters of various sizes have been extensively studied in recent years, − mainly in relation to their magnetic properties, which are, at the same time, strongly determined by their geometry and electronic characteristics …”

Section: Introductionmentioning

confidence: 99%

Structural, Electronic, and Magnetic Properties of Small Ni Clusters

Estiú

Zerner

1996

J. Phys. Chem.

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The electronic structure and magnetic properties of small Ni n clusters (n = 4, 5, 6, 8, 13) are studied at the self-consistent-field multireference configuration interaction singles level using the intermediate neglect of differential overlap model Hamiltonian parametrized for spectroscopy. Results are in agreement with density functional theory calculations and ab initio calculations for the smaller (n = 4−6) structures. Discrepancies develop for the larger (n = 8, 13) structures, and these discrepancies are discussed. We examine systems and criteria for the selection of the cluster size that most accurately model heterogeneous catalysts.

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Magnetic properties of nanometric nickel particles

Cited by 9 publications

References 9 publications

Electric field-assisted levitation-jet aerosol synthesis of Ni/NiO nanoparticles

Electric field-assisted levitation-jet aerosol synthesis of Ni/NiO nanoparticles

Structure and properties of cobalt clusters up to the tetramer: A density-functional study

Structural, Electronic, and Magnetic Properties of Small Ni Clusters

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