Patent ID: 6985338

Claim:
A magnetic disk drive having a housing, a magnetic disk rotatably supported in the housing, a rotary actuator adapted to position a transducer-carrying slider above a recording surface of the magnetic disk, and a GMR sensor formed as part of the transducer, the sensor being adapted to sense magnetically recorded information on the recording surface, and comprising: a multilayer stack that includes: a ferromagnetic free layer having a substantially free magnetic moment; a ferromagnetic pinned layer having a substantially fixed magnetic moment oriented generally perpendicular to said free layer magnetic moment; a nonmagnetic electrically conductive spacer layer sandwiched between said pinned layer and said free layer; an in-stack, electrically insulative hard biasing layer adapted to bias said free layer, said hard biasing layer having a substantially fixed magnetic moment oriented substantially antiparallel to a zero bias point of said free layer magnetic moment; and an insulative spacer layer between said free layer and said hard biasing layer; said insulative spacer layer separating said hard biasing layer from said free layer so that said free layer is biased by way of a magneto-static coupling that stabilizes said free layer magnetic moment without pinning said free layer via exchange coupling; and a pair of electrodes respectively disposed on either side of said multilayer stack and in contact with said free layer, said pineed layer, said conductive spacer layer, said insulative hard biasing layer and said insulative spacer layer; said electrodes being adapted to pass electrical current through said multilayer stack while said insulative hard biasing layer and said insulative spacer layer prevent current shunting away from said free layer, said pinned layer and said conductive spacer layer by virtue of being electrically insulative.