Outstanding Magnetic Properties of Nematic Suspensions of Goethite ( <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi></math></span>-FeOOH) Nanorods

B. J. Lemaire; P. Davidson; J. Ferré; J. P. Jamet; P. Panine; I. Dozov; J. P. Jolivet

doi:10.1103/PhysRevLett.88.125507

Outstanding Magnetic Properties of Nematic Suspensions of Goethite ( $α$ -FeOOH) Nanorods

B. J. Lemaire, P. Davidson, J. Ferré, J. P. Jamet, P. Panine, I. Dozov, and J. P. Jolivet

Phys. Rev. Lett. 88, 125507 – Published 11 March 2002

Abstract

Aqueous suspensions of goethite ( $α$ -FeOOH) nanorods form a mineral lyotropic nematic phase that aligns in a very low magnetic field (20 mT for samples 20 $μ m$ thick). The particles orient along the field direction at intensities smaller than 350 mT, but they reorient perpendicular to the field beyond 350 mT. This outstanding behavior is also observed in the isotropic phase which has a very strong magnetic-field induced birefringence that could be interesting for applications. We interpret these magnetic effects as resulting from a competition between a nanorod remanent magnetic moment and a negative anisotropy of its magnetic susceptibility.

Received 11 October 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.125507

Authors & Affiliations

B. J. Lemaire¹, P. Davidson^1,*, J. Ferré¹, J. P. Jamet¹, P. Panine², I. Dozov³, and J. P. Jolivet⁴

¹Laboratoire de Physique des Solides, UMR CNRS 8502, Bâtiment 510, Université Paris-Sud, 91405 Orsay, France
²European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble, France
³Nemoptic, 1 rue Guynemer, 78114 Magny-les-Hameaux, France
⁴Laboratoire de Chimie de la Matière Condensée, UMR CNRS 7574, Université Paris 6, 4 Place Jussieu, 75252 Paris, France