On the concentration and wavelength dependence of the degree of polarization in magnetic fluids

The concentration and wavelength dependence of the degree of polarization of light at room temperature in diluted Fe3O4 particle magnetic fluids has been investigated. The volumic fraction epsilon of the samples investigated ranged from 0.548 to 10.36 x 10(-3). The range of wavelengths lambda used in this study was 366-905 nm. Applied measuring magnetic fields up to 8 k Oe were used. For a given concentration, the degree of polarization, D, increases rapidly with the field at low fields, then less rapidly at intermediate fields, and tends to saturate at high fields. Also, D increases with increasing concentration. The results also show that the degree of polarization increases with frequency at low frequencies (in the optical region), reaching a maximum at similar to nu=6 x 10(14) Hz, and then decreases for higher frequencies.