Abstract : 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.
https://hal-cea.archives-ouvertes.fr/cea-01394919
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Submitted on : Thursday, November 10, 2016 - 10:38:31 AM Last modification on : Friday, March 5, 2021 - 3:11:44 PM Long-term archiving on: : Wednesday, March 15, 2017 - 3:11:24 AM
K. Komatsu, D. l'Hote, S. Nakamae, F. Ladieu, V. Mosser, et al.. Magnetic noise of a frozen ferrofluid. Journal of Applied Physics, American Institute of Physics, 2010, 107, pp.09E140. ⟨10.1063/1.3366613⟩. ⟨cea-01394919⟩