Small Angle X-ray Scattering Study of Magnetic Nanofluid Exposed to an Electric Field

Abstract

We report on the investigation of a transformer oil-based magnetic nanofluid exposed to an electric field bymeans of synchrotron small angle X-ray scattering. Two types of small angle X-ray scattering experiments werecarried out. In the first one, the electric field up to 6 kV/cm was generated in the nanofluid between two immersedelectrodes. The other experiment focused on the nanofluid in an external electric field up to 10 kV/cm, whenthe electrodes were not in a direct electrical contact with the nanofluid. In the available range (0.02–4.5 nm−1)of scattering vectorq, the non-contact mode has no effect on the scattering intensity. The contact mode yieldednoticeable low-qintensity variations. In comparison to small angle neutron scattering, the small angle X-rayscattering study did not prove the proportional increase in the lowqscattering intensity with increasing electricfield, but rather stochastic variations. The observed intensity variations reflect the local structural nanofluidchanges caused by the induced electrohydrodynamics. The electrical conductivity and relaxation processes arepointed out as favorable conditions for electrohydrodynamics in the magnetic nanofluid.