A data storage device can transition a functional data storage medium into a read only data surface. Data can be written to a data storage medium with a data writer of a transducing head prior to a security threat being identified. A write head of the transducing head is deactivated in response to the security threat by selecting a permanent deactivation mechanism.

A PMR writer with a true one turn design is disclosed with a driving coil above the main pole (MP) but where a bucking coil below the MP is replaced by a dummy metal layer or fully removed to substantially enhance the return field to the trailing shield. A non-double write shield scheme is employed where the leading loop for magnetic flux return is terminated at the leading shield. A tapered bottom yoke (tBY) contacts the MP bottom surface and has a tapered front side at height tBYd from the air bearing surface. Bottom yoke (BY) is below the tBY and has a front side at height BYd where BYd>tBYd. Reader-writer separation is reduced by 1-2 microns when the bucking coil is fully removed. Wide adjacent track erasures are controlled with a high damping material in one or more of the leading, side and trailing shields.

A data storage device can transition a functional data storage medium into a read only data surface. Data can be written to a data storage medium with a data writer of a transducing head prior to a security threat being identified. A write head of the transducing head is deactivated in response to the security threat by selecting a permanent deactivation mechanism.

According to one embodiment, a disk-like magnetic recording medium includes a disk-like substrate, a first soft magnetic layer provided on the disk-substrate, a nonmagnetic spacer layer provided on the first soft magnetic layer, a second soft magnetic layer provided on the nonmagnetic spacer layer and antiferromagnetically exchange-coupled with the first soft magnetic layer via the nonmagnetic spacer layer, a magnetic recording layer provided on the second soft magnetic layer, wherein strength of an exchange coupling magnetic field Hbias decreases from an inner circumferential area toward an outer circumferential area of the disk-like magnetic recording medium.