Magneto-optical effects on gamma-Fe2O3 nanometric particles in polyvinylic alcohol

We have examined the magneto-optical properties of a series of samples made of gamma-Fe2O3 nanometric particles dispersed in polyvinylic alcohol at different concentrations. Faraday rotation spectra are measured. They show the presence of characteristic iron ion transitions whose amplitude are correlated with the gamma-Fe2O3 content. At low wavelength we observe a magneto-optical transition connected to the polymer matrix. Faraday rotation as a function of temperature shows that the magnetization tends to saturate at a sufficiently low temperature which depends on concentration.