title: Time dependence of the magnetic grain concentration and secondary grain aggregation in ferronematic lyotropic liquid crystals subjected to magnetic field gradients.
abstract: The dynamical behavior of lyotropic nematic liquid crystals doped with ionic and surfacted magnetic fluids (ferronematics) is studied using a linear optical technique. The response of these mesophases to a combination of a static and a pulsed magnetic field is investigated by measuring the relaxation times as a function of the pulse width. A reversible modification of the magnetic grain concentration in the bulk of the samples and a secondary aggregation process due to the presence of a field gradient introduced by the pulsed field is discussed.
authors.affiliation: Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05315-970, São Paulo, SP, Brazil.
authors.forename: C Y
authors.initials: CY
authors.lastname: Matuo
authors.forename: A M
authors.initials: AM
authors.lastname: Figueiredo Neto