Modeling neighborhood induced transition shift in perpendicular media with a soft underlayer

Summary form only given. This talk will describe modeling how magnetostatic fields from DC or low frequency regions in perpendicular media cause transition shift and track width broadening. There are two main types of mechanisms responsible for neighborhood induced transition shift (NITS). First is an indirect modulation of the write field due to flux coupling from the leading pole to the trailing pole through the yoke. The indirect case basically scales the total field by an amount that depends on the exact details of the writer as well as the written pattern. This leads to a shift in the position of the written transitions, where the sign of the shift depends on whether the transition is hard or easy relative to the NITS field. The width of the written track also varies by the same mechanism, creating a DC band at the track edges. The second method is a direct modulation of the write field due to properly imaged magnetostatic fields from the adjacent tracks. The direct case leads to the same basic effects, but is more complicated because the demagnetizing field does not simply scale the applied field. This can lead to an increased DC band relative to transition shift.