NARROW TRACK DUAL MAGNETORESISTIVE HEADS FOR TAPE

An experimental investigation of a dual magnetoresistive head tested on a Metrum tape test stand, is presented. The dual magnetoresistive (DMR) head has a trackwidth of 4 μm and a gap length of 0.1 μm. Metal particle tape, with a Mrδ of 16 memu/cm2 and a coercivity of 1.8 kOe, was used. A square wave was recorded with an FeAlN thin film inductive head, with a trackwidth of 33 μm and a gap of 1.9 μm. A shielded shunt biased MR head used in quarter inch cartridge drives (QIC), with a trackwidth of 19 μm and a shield to element gap of 0.25 μm was used as a benchmark. The DMR head showed a larger signal to dc erased noise per unit trackwidth than the QIC MR head, at linear densities of 20 to 100 kfci. Isolated transitions and dibits with a bit spacing of 0.3 μm were recorded for time domain measurements. The dibit response of the DMR head, characterized by a unipolar pulse with small side over/undershoots demonstrated the differential character of the DMR head. The QIC MR head PW50, measured directly from the...