Particles size dependence of Faraday rotation in maghemite ferrofluid

This paper reports on experimental results which evidence particles size effects on Faraday rotation induced in ferrofluids. The four ferrofluid samples studied here are all issued from the same initial ferrofluid. Using a separation phase method their diameter size distributions are centered around four different values, their volume fraction of particles being adjusted to the same level. Optical and magneto-optical measurements on theses samples show that using small diameters provides a large increase of the factor of merit of this material.