MAGNETIZATIONS OF PINNED AND FREE LAYERS OF A SPIN VALVE SENSOR SET BY SENSE CURRENT FIELDS

摘要

A self-biasing magnetoresistive (MR) spin valve sensor (140) is provided whichdoes not require an antiferromagnetic layer for orienting magnetizations. A non-magnetic electrically-conducting spacer layer (146) is sandwiched between ferromagneticfree (142) and pinned (144) layers. A first flux guide is magnetically coupled to firstedges of the layers at the ABS and a second flux guide is magnetically coupled to secondedges of the free layer recessed from the ABS so that the effect of the demagnetizationfield [err] on the free layer is at least minimized and preferably zero. A sensecurrent (154) is directed through the spin valve sensor (140) so that the sense currentfield (154) from the pinned layer balances the ferromagnetic coupling (150) on the freelayer and the sense current field (156) from the free layer adds to the ferromagneticcoupling (150) on the pinned layer (144).