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Anisotropic magnetic particles in a magnetic field

Martchenko, Ilya LU ; Crassous, Jerome LU ; Mihut, Adriana M. LU ; Bialik, Erik LU ; Hirt, Ann M; Rufier, Chantal; Menzel, Andreas LU ; Dietsch, Hervé; Linse, Per LU and Schurtenberger, Peter LU (2016) In Soft Matter 12(42). p.8755-8767
Abstract

We characterize the structural properties of magnetic ellipsoidal hematite colloids with an aspect ratio ρ ≈ 2.3 using a combination of small-angle X-ray scattering and computer simulations. The evolution of the phase diagram with packing fraction φ and the strength of an applied magnetic field B is described, and the coupling between orientational order of magnetic ellipsoids and the bulk magnetic behavior of their suspension addressed. We establish quantitative structural criteria for the different phase and arrest transitions and map distinct isotropic, polarized non-nematic, and nematic phases over an extended range in the φ-B coordinates. We show that upon a rotational arrest of the ellipsoids around φ = 0.59, the bulk magnetic... (More)

We characterize the structural properties of magnetic ellipsoidal hematite colloids with an aspect ratio ρ ≈ 2.3 using a combination of small-angle X-ray scattering and computer simulations. The evolution of the phase diagram with packing fraction φ and the strength of an applied magnetic field B is described, and the coupling between orientational order of magnetic ellipsoids and the bulk magnetic behavior of their suspension addressed. We establish quantitative structural criteria for the different phase and arrest transitions and map distinct isotropic, polarized non-nematic, and nematic phases over an extended range in the φ-B coordinates. We show that upon a rotational arrest of the ellipsoids around φ = 0.59, the bulk magnetic behavior of their suspension switches from superparamagnetic to ordered weakly ferromagnetic. If densely packed and arrested, these magnetic particles thus provide persisting remanent magnetization of the suspension. By exploring structural and magnetic properties together, we extend the often used colloid-atom analogy to the case of magnetic spins.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
12
issue
42
pages
13 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:84993985710
  • wos:000386966900013
ISSN
1744-683X
DOI
10.1039/c6sm01411a
language
English
LU publication?
yes
id
e2373e21-042f-4489-9056-540a7a9ca775
date added to LUP
2017-02-23 13:55:59
date last changed
2017-10-22 05:27:18
@article{e2373e21-042f-4489-9056-540a7a9ca775,
  abstract     = {<p>We characterize the structural properties of magnetic ellipsoidal hematite colloids with an aspect ratio ρ ≈ 2.3 using a combination of small-angle X-ray scattering and computer simulations. The evolution of the phase diagram with packing fraction φ and the strength of an applied magnetic field B is described, and the coupling between orientational order of magnetic ellipsoids and the bulk magnetic behavior of their suspension addressed. We establish quantitative structural criteria for the different phase and arrest transitions and map distinct isotropic, polarized non-nematic, and nematic phases over an extended range in the φ-B coordinates. We show that upon a rotational arrest of the ellipsoids around φ = 0.59, the bulk magnetic behavior of their suspension switches from superparamagnetic to ordered weakly ferromagnetic. If densely packed and arrested, these magnetic particles thus provide persisting remanent magnetization of the suspension. By exploring structural and magnetic properties together, we extend the often used colloid-atom analogy to the case of magnetic spins.</p>},
  author       = {Martchenko, Ilya and Crassous, Jerome and Mihut, Adriana M. and Bialik, Erik and Hirt, Ann M and Rufier, Chantal and Menzel, Andreas and Dietsch, Hervé and Linse, Per and Schurtenberger, Peter},
  issn         = {1744-683X},
  language     = {eng},
  number       = {42},
  pages        = {8755--8767},
  publisher    = {Royal Society of Chemistry},
  series       = {Soft Matter},
  title        = {Anisotropic magnetic particles in a magnetic field},
  url          = {http://dx.doi.org/10.1039/c6sm01411a},
  volume       = {12},
  year         = {2016},
}