Magnetic stabilization and scissor design for anomalous hall effect magnetic read sensor

摘要

A system comprising a sensor with a free layer that exhibits an anomalous Hall effect is disclosed. Further, the sensor has a magnetic underlayer below the free layer in a track direction for biasing a magnetic orientation of the free layer in a first magnetic orientation, and a magnetic overlayer above the free layer in the track direction for biasing the magnetic orientation of the free layer in the first magnetic orientation. Still further, the sensor has a lower nonmagnetic spacer layer between the magnetic underlayer and the free layer, and an upper nonmagnetic spacer layer between the magnetic overlayer and the free layer.

主权项

1. A system, comprising:
a sensor having:
a first free layer;a second free layer above the first free layer in a track direction, the free layers exhibiting an anomalous Hall effect;a nonmagnetic spacer layer between the first free layer and the second free layer;a magnetic underlayer below the first free layer in the track direction for biasing a magnetic orientation of the first free layer in a first magnetic orientation;a magnetic overlayer above the second free layer in the track direction for biasing a magnetic orientation of the second free layer in a second magnetic orientation antiparallel to the first magnetic orientation;a lower nonmagnetic spacer layer between the magnetic underlayer and the first free layer; andan upper nonmagnetic spacer layer between the magnetic overlayer and the second free layer; a first set of electrodes configured to pass a current through the first free layer and the second free layer in a first direction; and at least one second electrode configured to allow measurement of a Hall voltage of the first free layer and the second free layer in a second direction orthogonal to the first direction; wherein a magnetic orientation of the magnetic overlayer is oriented antiparallel to the magnetic orientation of the second free layer, and a magnetic orientation of the magnetic underlayer is oriented antiparallel to the magnetic orientation of the first free layer; wherein the sensor is configured such that the Hall voltage is substantially 0 volts when the sensor is at a quiescent state.