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Title: Magnetic-field-induced orientational order in the isotropic phase of hard colloidal platelets

Abstract

The magnetic-field-induced orientational order in the isotropic phase of colloidal gibbsite [Al(OH){sub 3}] platelets is studied by means of optical birefringence and small-angle x-ray scattering (SAXS) techniques. The suspensions display field-induced ordering at moderate field strengths (a few Tesla), which increases with increasing particle concentration. The gibbsite particles align their normals perpendicular to the magnetic field and hence possess a negative anisotropy of their diamagnetic susceptibility {delta}{chi}. The results can be described following a simple, Onsager-like approach. A simplified model is derived that allows one to obtain the orientational distribution function directly from the scattering data. However, it leads to an underestimate of the diamagnetic susceptibility anisotropy {delta}{chi}. This accounts for the difference between the {delta}{chi} values provided by the two experimental techniques (SAXS and magneto-optics). The order of magnitude {delta}{chi}{approx}10{sup -22} J/T{sup 2} lies in between that of goethite suspensions and that of suspensions of organic particles.

Authors:
; ; ;  [1]; ; ;  [2];  [3];  [4]
  1. Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands)
  2. Laboratoire de Physique des Solides, UMR 8502 CNRS, Universite Paris-Sud, Batiment 510, 91405 Orsay (France)
  3. Institut fuer Theoretische Physik II, Heinrich-Heine-Universitaet Duesseldorf, Universitaetsstrasse 1, Gebaeude 25.32, 40225 Duesseldorf (Germany)
  4. Netherlands Organisation for Scientific Research (NWO), DUBBLE CRG, European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France)
Publication Date:
OSTI Identifier:
20779237
Resource Type:
Journal Article
Journal Name:
Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
Additional Journal Information:
Journal Volume: 73; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevE.73.041402; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-651X
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM HYDROXIDES; ANISOTROPY; BIREFRINGENCE; COLLOIDS; DIAMAGNETISM; DISTRIBUTION FUNCTIONS; GIBBSITE; GOETHITE; MAGNETIC FIELDS; MAGNETIC SUSCEPTIBILITY; MAGNETO-OPTICAL EFFECTS; PARTICLES; SMALL ANGLE SCATTERING; SUSPENSIONS; X-RAY DIFFRACTION

Citation Formats

Beek, D. van der, Petukhov, A.V., Vroege, G.J., Lekkerkerker, H.N.W., Davidson, P., Ferre, J., Jamet, J.P., Wensink, H.H., and Bras, W. Magnetic-field-induced orientational order in the isotropic phase of hard colloidal platelets. United States: N. p., 2006. Web. doi:10.1103/PHYSREVE.73.0.
Beek, D. van der, Petukhov, A.V., Vroege, G.J., Lekkerkerker, H.N.W., Davidson, P., Ferre, J., Jamet, J.P., Wensink, H.H., & Bras, W. Magnetic-field-induced orientational order in the isotropic phase of hard colloidal platelets. United States. doi:10.1103/PHYSREVE.73.0.
Beek, D. van der, Petukhov, A.V., Vroege, G.J., Lekkerkerker, H.N.W., Davidson, P., Ferre, J., Jamet, J.P., Wensink, H.H., and Bras, W. Sat . "Magnetic-field-induced orientational order in the isotropic phase of hard colloidal platelets". United States. doi:10.1103/PHYSREVE.73.0.
@article{osti_20779237,
title = {Magnetic-field-induced orientational order in the isotropic phase of hard colloidal platelets},
author = {Beek, D. van der and Petukhov, A.V. and Vroege, G.J. and Lekkerkerker, H.N.W. and Davidson, P. and Ferre, J. and Jamet, J.P. and Wensink, H.H. and Bras, W.},
abstractNote = {The magnetic-field-induced orientational order in the isotropic phase of colloidal gibbsite [Al(OH){sub 3}] platelets is studied by means of optical birefringence and small-angle x-ray scattering (SAXS) techniques. The suspensions display field-induced ordering at moderate field strengths (a few Tesla), which increases with increasing particle concentration. The gibbsite particles align their normals perpendicular to the magnetic field and hence possess a negative anisotropy of their diamagnetic susceptibility {delta}{chi}. The results can be described following a simple, Onsager-like approach. A simplified model is derived that allows one to obtain the orientational distribution function directly from the scattering data. However, it leads to an underestimate of the diamagnetic susceptibility anisotropy {delta}{chi}. This accounts for the difference between the {delta}{chi} values provided by the two experimental techniques (SAXS and magneto-optics). The order of magnitude {delta}{chi}{approx}10{sup -22} J/T{sup 2} lies in between that of goethite suspensions and that of suspensions of organic particles.},
doi = {10.1103/PHYSREVE.73.0},
journal = {Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics},
issn = {1063-651X},
number = 4,
volume = 73,
place = {United States},
year = {2006},
month = {4}
}