Nanocomposite magnetic films for high-density perpendicular magnetic recording media

Multi-layer nanocomposite structures of Ta/Ru/CoCr1/FeCoTaCr(soft magnetic layer)/CoCr2/CoCrPt–SiO2(hard magnetic layer or recording layer)/C and Ta/Ru/CoCr1/CoCrPt–SiO2/CoCr2/FeCoTaCr/C were proposed. This exchange coupled composite (ECC) media consisting of hard/soft stacked magnetic layers were promising in improving the writability of perpendicular magnetic recording media. A small CoCrPt c-axis orientation dispersion of about 3° was achieved with the optimized sputter conditions. The CoCrPt–SiO2 grains were well segregated by SiO2 at grain boundaries. The macro-magnetic properties showed that the stacked magnetic grains switched in a coherent mode and that switching field decreased with increasing the thickness of the soft magnetic layer.