THE WAVELENGTH AND CONCENTRATION-DEPENDENCE OF THE MAGNETO-DIELECTRICANISOTROPY EFFECT IN MAGNETIC FLUIDS DETERMINED FROM MAGNETOOPTICAL MEASUREMENTS

The concentration and wavelength dependence of the magneto-dielectric anisotropy effect in magnetic fluids has been investigated. Our result s show that the field-induced change in the dielectric constants for l ight polarized in the field direction increases with the applied field while that for light polarized perpendicular to the held decreases wi th the field. Furthermore, our results show that this held-induced cha nge is linear with concentration. The results also show that the field -induced change, for light polarized in the field direction, increases with frequency till it reaches a peal; at a given frequency and then decreases with further increase in frequency; while for light polarize d perpendicular to the field, it decreases with frequency till it reac hes a minimum at a given frequency and then increases with further inc rease in frequency. Moreover, our results yield a value of two for the magneto-dielectric anisotropy factor. (C) 1998 Elsevier Science B.V. All rights reserved.