Magneto-Optical Fe/Tb/Nd/Tb Multilayers: Anisotropy and Kerr Rotation

摘要

To increase the recording density of magneto-optic materials, they have to fulfill some special features: High coercivity H_C, Curie-temperature Tc between 100 and 200°C, measurable Kerr rotation θ_K at low wavelengths, perpendicular magnetic anisotropy and rectangular shaped magnetization loops. For the commercial magneto-optical applications FeTbCo-alloys are used. This conventional material does not suffice the requirements of high density storage media at the wavelength of blue laser beam. For this propose the idea was born to combine Fe/Tb-multilayers with the light rare-earth metal neodymium to increase the Kerr rotation [2], To study the magnetic properties of such systems, different multilayer setups, including the elements iron, terbium and neodymium, were sputter deposited. These multilayers were analyzed magnetically with a vibrating sample- (VSM), a torque magnetometer (TOM) and with a polar magneto-optical Kerr-effect-instrument (PMOKE), respectively a Kerr-spectrometer to find the best layer combination for fulfilling the above named features.