Patent ID: 8780506

Claim:
A magnetoresistive sensor structure for sensing magnetically recorded data from a magnetic recording medium, the structure comprising: a substrate; a magnetoresistive sensor comprising a stack of layers including a ferromagnetic free layer on a central region of the substrate and having a front edge for facing a magnetic recording medium and two spaced-apart side edges, the sensor being capable of sensing magnetically recorded data when a sense current is applied perpendicular to the planes of the layers in the sensor stack; a side shield on each of two side regions of the substrate adjacent said central region of the substrate, each side shield formed of an alloy comprising Ni and Fe wherein the amount of Fe is greater than or equal to 15 atomic percent and less than or equal to 25 atomic percent of the total of Ni and Fe in said alloy, each side shield having its magnetization oriented generally parallel to said sensor front edge and generally parallel to the plane of said free layer; and a top shield on the sensor and the two side shields comprising an antiparallel structure (APS) having first and second ferromagnetic layers, a nonmagnetic antiparallel coupling (APC) film between said first and second ferromagnetic layers that couples said first and second ferromagnetic layers together antiferromagnetically, and one and only one ferromagnetic interface film between and in contact with said APC film and one and only one of said APS first and second ferromagnetic layers, the interface film selected from Co and a CoFe alloy.