Optimization of heads for perpendicular recording

The effects of gap length, head-underlayer separation, and return pole potential on the magnitude and direction of the field of a gapped head are investigated using an analytic two-dimensional model. Criteria derived from a micromagnetic model of a perpendicular recording medium are used to optimize the head geometry for various media parameters. A head with a gap length which is at most 2.5 times the head-medium separation can write on higher coercivity media than a single pole.