Low inductance and high efficiency single-pole writing head for perpendicular double layer recording media

A new type of thin film inductive single-pole head for perpendicular magnetic recording has been developed to provide a writing head for perpendicular double layer media. The head consisted of a main pole, three thin-film conductive layers to drive the pole and a return path pole. A low inductance of around 1.5 nH and a small saturation magneto-motive force of less than 0.025 AT_0.p was obtained. The D₅₀ was 180 kFRPI with an MR head of 210 nm shield separation. The error rate at 310 kFRPI was 10^-6. Head induced erasure, which is an issue for the single-pole head, was also investigated by experiments and calculations. Around 10% output reduction in 20 Oe stray field was confirmed. Computer simulation predicted an improvement by reducing the permeability of the medium´s underlayer