Issues in recording exchange coupled composite media

Exchange coupled composite (ECC) media exhibits a lower switching field than conventional perpendicular media at the same level of thermal stability, and thus is able to achieve higher areal density. The inhomogeneity of ECC media is predicted to enhance the thermal attempt frequency: this increases both writability and adjacent track erasure (ATE). The adverse change in ATE is, however, countered by the angular dependence of the ECC media switching field. This angular dependence is further exploited with a head design featuring a larger pole width than track width and the introduction of notches in the down track direction. This reduces the effect of head skew and increases the write field. An optimized head is found to be consistent with terabit/in² recording.