MAGNETIC-STRUCTURES IN CO-CR MEDIA FOR PERPENDICULAR MAGNETIC RECORDING

High bit densities have been demonstrated in longitudinal as well as i n perpendicular magnetic recording. For the latter an area density of more than 12 Gbit/in(2) has been obtained in a sputtered Co-Cr-Ta hard disk with a soft magnetic underlayer recorded with a special single p ole head. In this paper the role of microstructure and morphology in r elation to the compositional separation is discussed. Very sensitive a nomalous Hall measurements have been performed from submicron Co-Cr sa mples to obtain more detail information about the reversal characteris tics of the material. The results obtained have been used in our model for micromagnetic simulations. One of the conclusions is that most of the magnetic entities reversing their magnetisations are much smaller than the volume of one Co-Cr column.