Patent ID: 8670217
Filing Date: 2014-03-11
Classification: B82Y,G11B

Abstract:
1. A magnetoresistive sensor capable of sensing external magnetic fields when a sense current is applied perpendicular to the planes of the layers in the sensor, the sensor comprising: a substrate; a first free layer on the substrate, the first free layer being an exchange-coupled structure comprising a patterned layer of alternating ferromagnetic stripes and nonmagnetic stripes and an unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer, the first free layer having an in-plane magnetization direction substantially free to rotate in the presence of an external magnetic field to be sensed; a nonmagnetic spacer layer on the first free layer; and a second free layer on the spacer layer, the second free layer being an exchange-coupled structure comprising a patterned layer of alternating ferromagnetic stripes and nonmagnetic stripes and an unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer, the second free layer having an in-plane magnetization direction substantially free to rotate in the presence of an external magnetic field to be sensed.