A magnetic structure for use in a magnetic head for avoiding wide angle
track erasure and other forms of adjacent track interference. The
magnetic structure includes a trailing shield having a specially
configured back edge opposite the air bearing surface ABS. The magnetic
shield has a shallow substantially constant throat height at a center
portion. Then, the back edge of the shield tapers back away from the ABS
in first and second intermediate portion located at either side of the
center portion. These intermediate portions lead to first and second
outer portions that have substantially constant throat heights that are
larger than the throat height at the center region. The throat height at
each of the laterally outer portions can be 1.5 to 5 times the throat
height of the center portion. This configuration, chokes off stray fields
that might be picked up by the outer portions of the shield preventing
excessive magnetic flux from reaching the central portion of the shield
where it might affect writing. In addition, the limited throat height of
the outer portion (ie. the back edge of the outer portions does not keep
tapering back away from the ABS) prevents the outer portions from picking
up too much stray magnetic field, while also ensuring that sufficient
magnetic material will be present to absorb desired magnetic field from
the write pole during use.