A method of forming a read head. The method includes forming first and second read sensors. A first read measurement is performed on a storage medium using the first read sensor. A second read measurement is performed on the storage medium using the second read sensor. Based on a comparison of the first and second read measurements to a predetermined quantity, either the first read sensor or the second read sensor is selected to be operational in a data storage device.

A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. Alternatively, the HM may replace a shield domain. The top shield may have various shapes including a ring shape in which the HM stabilizes a vortex magnetization. In a whole shield coupling design, the HM contacts all of the top shield bottom surface except over the sensor and junction shield. HM magnetization is set or reset from room temperature to 100 C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.

A magnetic read apparatus has an air-bearing surface (ABS) and includes a read sensor and a rear magnetic bias structure. The read sensor includes first and second free layers, a spacer layer and a rear surface opposite to the ABS. The spacer layer is nonmagnetic and between the first and second free layers. The read sensor has a track width in a cross track direction parallel to the ABS. The rear magnetic bias structure magnetically biases the read sensor a stripe height direction perpendicular to the ABS. The read sensor is between the ABS and the rear magnetic bias structure. The rear magnetic bias structure has a width in the cross track direction and a length in the stripe height direction. The length is greater than the width. The width of the rear magnetic bias structure is substantially equal to the track width of the read sensor.

An apparatus according to one embodiment includes a magnetic head having multiple magnetic transducers, the transducers including read sensors. The read sensors are of at least two differing types selected from a group consisting of tunneling magnetoresistance (TMR), giant magnetoresistance (GMR), anisotropic magnetoresistance (AMR), and inductive sensors.

A system according to one embodiment includes a magnetic head having a plurality of sensors arranged to simultaneously read at least three immediately adjacent data tracks on a magnetic medium, wherein none of the sensors share more than one lead with any other of the sensors. Such embodiment may be implemented in a magnetic data storage system such as a disk drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., hard disk) over the magnetic head, and a controller electrically coupled to the magnetic head.

A multi reader head has a plurality of readers that are laminated via a gap layer(s), and each of the readers has a structure in which a current-perpendicular-to-plane (CPP) type of magneto-resistive effect element, where a current flows along the lamination direction, is interposed between a pair of shields that function as an electrode, respectively, from both sides in the lamination direction. The shields that are opposed from each other via the gap layer of the readers that are adjacent in the lamination direction by a distance that is not constant, but include a portion with a greater distance between the shields and another portion with a smaller distance between the shields are included. The portion with a greater distance between the shields is situated at a position away from the center on an air bearing surface opposing to a recording medium in the magneto-resistive effect element.

A multi reader head has a plurality of readers that are laminated via a gap layer(s), and each of the readers has a structure in which a current-perpendicular-to-plane (CPP) type of magneto-resistive effect element, where a current flows along the lamination direction, is interposed between a pair of shields that function as an electrode, respectively, from both sides in the lamination direction. The shields that are opposed from each other via the gap layer of the readers that are adjacent in the lamination direction by a distance that is not constant, but include a portion with a greater distance between the shields and another portion with a smaller distance between the shields are included. The portion with a greater distance between the shields is situated at a position away from the center on an air bearing surface opposing to a recording medium in the magneto-resistive effect element.

A lateral spin valve reader that includes a detector structure located proximate to a bearing surface and a spin injection structure located away from the bearing surface. The lateral spin valve reader also includes a channel layer extending from the detector structure to the spin injection structure. An exterior cladding, disposed around the channel layer, suppresses spin-scattering at surfaces of the channel layer.

A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.

A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.