Long-Range Erasure of Nearby Recorded Tracks

Abstract

A thin-film write element at 0/spl deg/ skew angle can produce partial erasure, affecting previously recorded tracks as far as 2 /spl mu/m away. This symmetric erasure is due to fringe fields from the write gap or adjacent to the gap side of the leading pole. The amount of erasure varied with the design of the write yoke, and a yoke made with a higher saturation moment material also produced more erasure. Disks with lower coercivities and multilayered recording media were more easily erased. The erasure was also aggravated by increasing the flat-to-flat write current, the amount of write current overshoot, and the frequencies of both the aggressor and victim data tracks. There was no correlation between the amount of this off-track erasure and the on-track overwrite. The amplitude reduction increased logarithmically with the number of aggressor write operations.