Magnetic field induced assembling of nanoparticles in ferrofluidic liquid thin films based on NixFe1-xFe2O4

Ultra fine precursors for ferrofluid synthesis, belonging to the series, NixFe1-xFe2O4 (where 'x' varies from '0' to '0.6' in steps of 0.1), were synthesized. Ferrofluids based on these fine particles were prepared with oleic acid as surfactant and kerosene as carrier. Ferrofluidic thin films were made on glass substrates and magnetic field induced laser transmission was studied. The pattern exhibited by the films under the influence of a magnetic field was observed with the help of a CCD camera. The analysis of results confirms the chain formation of particles in the presence of an applied magnetic field and their saturation at higher applied fields.