Magnetic noise of a frozen ferrofluid

K. Komatsu (1) , D. L'Hote (1, 2) , S. Nakamae (1) , F. Ladieu (1, 2) , V. Mosser (3) , A. Kerlain (3) , M. Konczykowski (4) , Emeric Dubois (5) , V. Dupuis (5) , R. Perzynski (5)

1 SPHYNX - Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes
2 SPEC - UMR3680 - Service de physique de l'état condensé
3 ITRON SAS
4 LSI - Laboratoire des Solides Irradiés
5 PECSA - Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques

The magnetic noise of a frozen ferrofluid made of maghemite nanoparticles dispersed in glycerin is measured using a two-dimensional electron gas based quantum well Hall sensor QWHS with the spinning current technique. The frozen ferrofluid shows a superspin glass transition at 67 K. Below this glass transition temperature, the relation between the imaginary part of the ac susceptibility of a bulk ferrofluid sample and the magnetic noise measured with the QWHS gives an indication of a violation of the fluctuation dissipation theorem.

Domains: Physics [physics]

K. Komatsu, D. L'Hote, S. Nakamae, F. Ladieu, V. Mosser, et al.. Magnetic noise of a frozen ferrofluid. Journal of Applied Physics, 2010, 107, pp.09E140. ⟨10.1063/1.3366613⟩. ⟨cea-01394919⟩