Measurements of magnetoresistance in magneto-optical recording media

The magnetoresistance effect in compositionally modulated transition-metal/transition-metal films (Co/Pt and Co/Pd) and in amorphous binary rare-earth-transition-metal alloy films (TbFe) has been investigated. Results of measurements on several samples at room temperature as a function of the strength of the applied magnetic field are reported. For each sample three different configurations are investigated in which the direction of the applied field is (i) perpendicular to the plane of film, (ii) in the plane of the film and parallel to the direction of the electric current, (iii) in the plane of the film and perpendicular to the direction of the current. During these measurements the extraordinary Hall effect and the magneto-optic Kerr effect have also been monitored. This additional information, together with the magnetization measurement results obtained from a vibrating sample magnetometer, are used to analyze the data and to explain some of their interesting features.