Patent ID: 7027271

Claim:
A magnetoresistive device comprising: a magnetoresistive element having two surfaces that face toward opposite directions and two side portions that connect the two surfaces to each other; two bias field applying layers that are located adjacent to the side portions of the magnetoresistive element and apply a bias magnetic field to the magnetoresistive element; and two electrode layers that feed a current used for signal detection to the magnetoresistive element, each of the electrode layers being adjacent to one of surfaces of each of the bias field applying layers, wherein: at least one of the electrode layers overlaps one of the surfaces of the magnetoresistive element; the magnetoresistive element incorporates: a nonmagnetic layer having two surfaces that face toward opposite directions; a soft magnetic layer adjacent to one of the surfaces of the nonmagnetic layer; a pinned layer, located adjacent to the other one of the surfaces of the nonmagnetic layer, whose direction of magnetization is fixed; and an antiferromagnetic layer located adjacent to one of surfaces of the pinned layer that is farther from the nonmagnetic layer, the antiferromagnetic layer fixing the direction of magnetization of the pinned layer; the pinned layer includes a nonmagnetic spacer layer and two ferromagnetic layers that sandwich the spacer layer and have directions of magnetization fixed to opposite directions; a total length of regions of the two electrode layers that are laid over the one of the surfaces of the magnetoresistive element is smaller than 0.3 μm; and a space between the two electrode layers is equal to or smaller than approximately 0.4 μm.