A Stepped-Pole Writer to Minimize Side Erasure on Barium Ferrite Tape

Side erasure is investigated for non-oriented and perpendicularly oriented barium ferrite particulate tape media without a soft-underlayer. While notching is efficient to avoid side writing from the leading pole, the perpendicular head fields originating from the outer edge of the trailing pole result in curved transitions and non-negligible side erasure. We find that such side erasure effects can be suppressed by recessing part of the trailing pole, thereby forming a stepped pole. Magnetic force microscopy and cross-track profiling experiments demonstrate the efficacy of this novel stepped-pole writer design to minimize side writing effects in non-oriented and perpendicular particulate tape media. This writer geometry will enable tape recording at 50 ktpi and beyond.