3-D head field modeling for perpendicular magnetic recording

In order to achieve areal densities in magnetic recording of the order of 1 Tbit/in/sup 2/ it has been suggested that a feasible system, based on current technologies, will involve a perpendicular head and a perpendicular medium with a soft magnetic underlayer. Micromagnetic modelling plays an important role in the design and analysis of recording systems and within any such calculation it is necessary to have accurate data on the magnetic field produced by the head. Numerical finite element and finite difference calculations are computationally intensive, particularly in 3D, but progress is now being made with 3D analytic models which take the magnetic underlayer into account. This paper reports on progress in that direction and in particular considers the geometry of a double-shielded perpendicular single pole head.