Improvement of switching field in AFC media by inserting Ru or CoCr layers in stabilizing Layer

The effects of Co insertion at the interface of CoCrPtB-Ru-CoCrPtB AFC media are investigated. Although the exchange coupling constant J can be increased by inserting Co, undesired magnetic properties are observed including reduction of the switching field of the stabilizing layer or reduction of coercivity of the recording layer. We propose a new antiferromagnetically coupled structure with a laminated stabilizing layer composed of CoCrPtB-(Ru or CoCr)-Co, in which Co remains at the interface to enhance J and a nonmagnetic layer Ru or CoCr is used for suppressing interaction between Co and lower CoCrPtB layer. The coercivity of the laminated stabilizing layer decreased and the switching field increases with increasing thickness of Ru or CoCr. Consequently, the insertion of Ru or CoCr can make the magnetization reversal of the stabilizing layer easier.