Magneto-optical response of isolated and embedded Fe nanoparticles

The magneto-optical response of nanometric Fe particles with varying size a nd shape has been studied, both in sputtered single layers and pulsed laser deposited nanocomposite films. The shape of Fe nanoparticles was controlle d by varying growth conditions. An effective medium theory for arbitrary pa rticle shapes has been derived and used to simulate the experimentally meas ured magneto-optical transverse Kerr spectra. The simulations show that the transverse Kerr magneto-optical spectra depend on the particles shape and correlate well with the experimentally determined spectra. From this result , it is deduced that Fe nanoparticles with dimensions down to 3-4 nm keep t heir bulk magneto-optical constants. On the other hand, large magneto-optic al signals are reported in multilayered structures due to interferential ef fects.