Patent ID: 8531801

Claim:
A magnetic transducer having an air-bearing surface (ABS) and comprising: a first shield; a read sensor including at least one edge; at least one magnetic bias structure adjacent to the at least one edge; and a second shield, the read sensor and the at least one magnetic bias structure residing between the first shield and the second shield, the second shield including a first ferromagnetic layer, a nonmagnetic spacer layer, a second ferromagnetic layer and a pinning layer, the nonmagnetic spacer layer residing between the first ferromagnetic layer and the second ferromagnetic layer, the first ferromagnetic layer residing between the read sensor and the nonmagnetic spacer layer, the pinning layer being adjacent to the second ferromagnetic layer, the first ferromagnetic layer being coupled antiparallel with the second ferromagnetic layer, the first ferromagnetic layer including a plurality of magnetic layers interleaved with at least one trilayer, each of the plurality of magnetic layers including a plurality of crystalline grains, the at least one trilayer including an amorphous nonmagnetic layer, the amorphous nonmagnetic layer being less than three Angstroms thick such that the plurality of magnetic layers are ferromagnetically coupled, the at least one trilayer being configured such that the plurality of crystalline grains in one of the plurality of magnetic layers are decoupled from the plurality of crystalline grains in another of the plurality of magnetic layers.