Magnetic properties of iron nanoparticles in mesoporous silica matrix

Grigorieva, N.A.; Grigoriev, S. V.; Eckerlebe, H.; Eliseev, A. A.; Napolskii, K. S.; Lukashin, A. V.; Tret’yakov, Yu. D.

doi:10.1016/j.jmmm.2005.10.116

Cited by 10 publications

(3 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since SANS is utilized in diverse fields of science such as biology, chemistry, physics or materials science, there exists an enormous body of research literature and, therefore, any realistic attempt to provide an encyclopedic listing is beyond the scope of this work. Magnetic SANS has been used to study a wide range of materials, including ferrofluids [20][21][22][23][24][25][26][27][28][29], nanoparticles and precipitates [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49], nanowires [50,51], magnetic recording media [52][53][54][55], collossal magnetoresistance materials [56][57][58], spin glasses and amorphous metals [59][60][61][62][63][64][65][66]…”

Section: Introductionmentioning

confidence: 99%

Magnetic-field-dependent small-angle neutron scattering on random anisotropy ferromagnets

Michels

Weißmüller

2008

Rep. Prog. Phys.

View full text Add to dashboard Cite

We report on the recently developed technique of magnetic-field-dependent small-angle neutron scattering (SANS), with attention to bulk ferromagnets exhibiting random magnetic anisotropy. In these materials, the various magnetic anisotropy fields (magnetocrystalline, magnetoelastic, and/or magnetostatic in origin) perturb the perfectly parallel spin alignment of the idealized ferromagnetic state. By varying the applied magnetic field, one can control one of the ordering terms which competes with the above-mentioned perturbing fields. Experiments which explore the ensuing reaction of the magnetization will therefore provide information not only on the field-dependent spin structure but, importantly, on the underlying magnetic interaction terms. This strategy, which underlies conventional studies of hysteresis loops in magnetometry, is here combined with magnetic SANS. While magnetometry generally records only a single scalar quantity, the integral magnetization, SANS provides access to a vastly richer data set, the Fourier spectrum of the response of the spin system as a function of the magnitude and orientation of the wave vector. The required data-analysis procedures have recently been established, and experiments on a number of magnetic materials, mostly nanocrystalline or nanocomposite metals, have been reported. Here, we summarize the theory of magnetic-field-dependent SANS along with the underlying description of random anisotropy magnets by micromagnetic theory. We review experiments which have explored the magnetic interaction parameters, the value of the exchange-stiffness constant as well as the Fourier components of the magnetic anisotropy field and of the magnetostatic stray field. A model-independent approach, based on the experimental autocorrelation function of the spin misalignment, provides access to the characteristic length of the spin misalignment. The field dependence of this quantity is in quantitative agreement with the predictions of micromagnetic theory. Experiments on nanocomposite ferromagnets reveal that the jump of the magnetization at internal phase boundaries leads to a significant magnetostatic perturbing field, with an unusual 'clover-leaf' SANS pattern as the experimental signature. Furthermore, SANS experiments have been used to monitor the orientation of magnetic domains as well as the length scale of intradomain spin misalignment.

show abstract

Section: Introductionmentioning

confidence: 99%

Magnetic-field-dependent small-angle neutron scattering on random anisotropy ferromagnets

Michels

Weißmüller

2008

Rep. Prog. Phys.

View full text Add to dashboard Cite

show abstract

“…Small angle neutron scattering with either partial or full polarization analysis has been shown to be a very effective probe of magnetic ordering for powdered collections of nanoparticles 5,[7][8][9][10]16,[20][21][22][23][24][25][26][27] . Here, we test further the nature of the interparticle magnetic correlations in ordered core-shell Fe 3 O 4 /Mn x Fe 3−x O 4 nanoparticle assemblies, making extensive use of full polarization-analyzed small-angle neutron scattering (PASANS) techniques [28][29][30] to characterize extensively the magnetic scattering over a range of field and temperature conditions.…”

mentioning

confidence: 99%

Correlated spin canting in ordered core-shellFe3O4/MnxFe3−xO4
Ijiri
¹
,
Krycka
²
,
Hunt-Isaak
³

et al. 2019
Phys. Rev. B
34
1
31
0
View full text Add to dashboard Cite

Polarization-analyzed small-angle neutron scattering methods are used to determine the spin arrangements and experimental length scales of magnetic correlations in ordered three-dimensional assemblies of ∼ 7.4 nm diameter core-shell Fe 3 O 4 /Mn x Fe 3−x O 4 nanoparticles. In moderate to high magnetic fields, the assemblies display a canted magnetic structure where the canting direction is coherent from nanoparticle to nanoparticle, in contrast to the less extended, more single particle-like behavior for similar ferrite assemblies. The observed magnetic scattering is modeled by assuming that the interparticle dipolar coupling combined with Zeeman effects in a field leads to nanoparticle domains with preferred net spin alignments relative to packing symmetry axes. Over a range of fields and temperatures, the model qualitatively explains the observed scattering anomalies in terms of clusters that vary in area and thickness, highlighting the complex structures adopted in real, dense nanoparticle systems. The clusters often have a strong two-dimensional magnetic character which is attributed to structural stacking faults and the resulting influence of interparticle dipolar interactions for these magnetically soft nanoparticles.

show abstract

“…Zerovalent iron (Fe 0 ) nanoparticles are of great physical and chemical importance and have attracted much attention in recent years for their magnetic (Grigorieva et al, 2006) and catalytic (Yan et al, 2008) properties, as well as their great potential in environmental remediation (Sarathy et al, 2010). Nevertheless, these Fe nanoparticles are easy to agglomerate and to oxidize, which makes them difficult to prepare, study, and apply (Huber, 2005;Bomatí-Miguel et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

A Critical Textural Evolution Study of Zerovalent Iron/Montmorillonite Nanosized Heterostructures Under Various Iron Loadings

Fan

Yuan

Bergaya

et al. 2011

Clays and clay miner.

View full text Add to dashboard Cite

Abstract-Heterostructures formed by nanoparticles hybridized with porous hosts are of great potential in many practical applications such as catalysis, adsorption, and environmental remediation, based on their intrinsic properties. The objectives of this study were to synthesize zerovalent iron nanoparticles/ montmorillonite heterostructures and to investigate their textural evolution under different Fe loadings. Iron nanoparticles were hybridized with montmorillonite by impregnation of montmorillonite by ferric ions followed by chemical reduction with sodium borohydride in solution. These hybridized Fe nanoparticles were well dispersed on the montmorillonite surface, size adjustable, and resistant to oxidation under the protection of native Fe-oxide shells. The textural evolution of these heterostructures under various Fe loadings was investigated using nitrogen physisorption, X-ray diffraction, electron microscopy, and elemental analyses. As the Fe loadings increased, the total pore and mesopore volumes were almost unchanged; the total, micropore, and external surface areas as well as the micropore volume decreased; and the average pore diameter increased. These textural changes could be attributed to the filling of the interparticle pores of montmorillonite by a variable amount of Fe nanoparticles. In addition, with increasing Fe loadings, the mesoporous character was enhanced for these heterostructures. These fundamental results are important in understanding the structure of these heterostructures as well as in developing some novel applications in related fields.

show abstract

Magnetic properties of iron nanoparticles in mesoporous silica matrix

Cited by 10 publications

References 6 publications

Magnetic-field-dependent small-angle neutron scattering on random anisotropy ferromagnets

Magnetic-field-dependent small-angle neutron scattering on random anisotropy ferromagnets

Correlated spin canting in ordered core-shellFe3O4/MnxFe3−xO4
Ijiri
¹
,
Krycka
²
,
Hunt-Isaak
³

et al. 2019
Phys. Rev. B
34
1
31
0
View full text Add to dashboard Cite

A Critical Textural Evolution Study of Zerovalent Iron/Montmorillonite Nanosized Heterostructures Under Various Iron Loadings

Contact Info

Product

Resources

About

Magnetic properties of iron nanoparticles in mesoporous silica matrix

Cited by 10 publications

References 6 publications

Magnetic-field-dependent small-angle neutron scattering on random anisotropy ferromagnets

Magnetic-field-dependent small-angle neutron scattering on random anisotropy ferromagnets

Correlated spin canting in ordered core-shellFe3O4/MnxFe3−xO4Ijiri1, Krycka2, Hunt-Isaak3 et al. 2019Phys. Rev. B341310View full textAdd to dashboardCite

A Critical Textural Evolution Study of Zerovalent Iron/Montmorillonite Nanosized Heterostructures Under Various Iron Loadings

Contact Info

Product

Resources

About

Correlated spin canting in ordered core-shellFe3O4/MnxFe3−xO4
Ijiri
¹
,
Krycka
²
,
Hunt-Isaak
³

et al. 2019
Phys. Rev. B
34
1
31
0
View full text Add to dashboard Cite