Complex microwave susceptibility of a ferrofluid with Mag-Hematite particles: nonreciprocal phenomena in magnetic liquids

We present susceptibility measurements on a ferrofluid in the microwave frequency range with three different measurement cells: a coaxial line, an X-band rectangular waveguide, and an X-band slab-loaded rectangular waveguide. We use the reflection/transmission method to obtain the complex susceptibility χ^*. We have subjected the cells to a constant magnetic field applied parallel or transversal to the propagation direction. We observe an increase of the gyromagnetic resonance phenomenon and some discrepancies between the consequences of a parallel or transverse applied field. Nonreciprocal phenomenon has been observed for the first time in a ferrofluid when a transversal field is applied to an X-band slab-loaded rectangular waveguide