Magnetic properties of soft layer/FePt--MgO exchange coupled composite perpendicular recording media

The magnetic properties of exchange coupled composite (ECC) media that are composed of perpendicular magnetic recording media FePt--MgO and two kinds of soft layers have been studied by using an x-ray diffractometer, a polar Kerr magneto-optical system (PMOKE) and a vibrating sample magnetometer (VSM). The results show that ECC media can reduce the coercivities of perpendicular magnetic recording media FePt--MgO. The ECC media with granular-type soft layers have weaker exchange couplings between magnetic grains and the magnetization process, for ECC media of this kind mainly follow the Stoner--Wohlfarth model.