Nonlinear response of a concentrated ferrofluid to a low-frequency magnetic field

A. A. Kuznetsov - A. V. Lebedev - A. F. Pshenichnikov

Institute of Continuous Media Mechanics of the Ural Branch, RAS, 1 Ac.~Korolev str., 614013 Perm, Russia

Abstract
Magnetic response of a concentrated polydisperse ferrofluid to a strong linearly polarized applied field is investigated both experimentally and theoretically. It is shown that in a wide range of particle concentrations and field amplitudes the second-order modified mean-field theory by Ivanov and Kuznetsova [2] well describes the experimentally observed magnetization spectra if the field frequency is low enough and internal relaxation processes in ferrofluid can be neglected. Tables 2, Figs 3, Refs 9.