An apparatus, according to one embodiment, includes: a module, and a plurality of tunnel valve read transducers arranged in an array extending along the module. Each of the tunnel valve read transducers includes: a sensor structure, an upper magnetic shield, a lower magnetic shield, an upper conducting spacer layer between the sensor structure and the upper magnetic shield, a lower conducting spacer layer between the sensor structure and the lower magnetic shield, and electrically insulating layers on opposite sides of the sensor structure. The sensor structure includes a cap layer, a free layer, a tunnel barrier layer, a reference layer and an antiferromagnetic layer. Moreover, a height of the free layer measured in a direction perpendicular to a media bearing surface of the module is less than a width of the free layer measured in a cross-track direction perpendicular to an intended direction of media travel.

An apparatus, according to one embodiment, includes: a module, and a plurality of tunnel valve read transducers arranged in an array extending along the module. Each of the tunnel valve read transducers includes: a sensor structure, an upper magnetic shield, a lower magnetic shield, an upper conducting spacer layer between the sensor structure and the upper magnetic shield, a lower conducting spacer layer between the sensor structure and the lower magnetic shield, and electrically insulating layers on opposite sides of the sensor structure. The sensor structure includes a cap layer, a free layer, a tunnel barrier layer, a reference layer and an antiferromagnetic layer. Moreover, a height of the free layer measured in a direction perpendicular to a media bearing surface of the module is less than a width of the free layer measured in a cross-track direction perpendicular to an intended direction of media travel.

In one general embodiment, an apparatus includes a magnetic head having at least one tunneling magnetoresistance sensor. The resistance of the tunnel barrier of each tunneling magnetoresistance sensor is about 25 ohms or less. In another general embodiment, an apparatus includes a magnetic head having at least one tunneling magnetoresistance sensor. The resistivity of the tunnel barrier of each tunneling magnetoresistance sensor is less than a product of a target resistance of the tunnel barrier and an area of the tunnel barrier. The target resistance is about 25 ohms or less.

The present disclosure generally relates to a dual free layer (DFL) two dimensional magnetic recording (TDMR) read head, and a method of forming thereof. The read head comprises a lower sensor, middle shields disposed on the lower sensor, and an upper sensor disposed on the middle shields. After the lower reader is formed, a dielectric layer is deposited around an outer perimeter of the lower shield. Portions of the dielectric layer are ion milled such that the remaining portions form a substantially flat layer. Another embodiment includes a deposition of a TaOx layer on the dielectric layer, where x is a numeral. Portions of the dielectric layer and the TaOx layer are then ion milled such that the remaining portions of the TaOx layer and the dielectric layer collectively form a substantially planar layer. The middle shields are formed over the lower reader and are substantially planar.

An apparatus according to one embodiment includes a sensor having an active region, a magnetic shield adjacent the active region, and a spacer between the active region and the magnetic shield. The spacer includes an electrically conductive ceramic layer. An apparatus according to another embodiment includes a sensor having an active tunnel magnetoresistive region, a magnetic shield adjacent the tunnel magnetoresistive region, and a spacer between the tunnel magnetoresistive region and the magnetic shields. The spacer includes an electrically conductive ceramic layer.

An apparatus for magnetic recording having a barrier layer. One embodiment includes a magnetic head having an array of sensors, each of the sensors having a media facing surface. A barrier layer is positioned above at least the media facing surfaces of the sensors. The barrier layer includes at least one at least partially polycrystalline layer.

An apparatus according to one embodiment includes a module having an array of first read transducers each having a tunnel valve structure and a second read transducer coupled to the array of first read transducers, the second read transducer having a tunnel valve structure. The apparatus also includes a controller, and a cable coupling the read transducers to the controller, thereby forming a plurality of circuits extending from the controller, each circuit corresponding to one of the transducers. Resistances of the circuits are about the same.

An apparatus according to one embodiment includes a first read transducer having a tunnel valve structure, and a second read transducer coupled to the first read transducer. The second read transducer has a tunnel valve structure as well, but the tunnel valve structure of the first read transducer has a different resistivity than the tunnel valve structure of the second read transducer. An apparatus according to another embodiment includes an array of first read transducers, each first read transducer having a tunnel valve structure. At least a second read transducer is coupled to the first read transducers, the second read transducer having a tunnel valve structure. The tunnel valve structure of the first read transducer has a different resistivity than the tunnel valve structure of the second read transducer.

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.

An apparatus according to one embodiment includes an array of magnetic read transducers each having a current-perpendicular-to-plane sensor, magnetic shields on opposite sides of the sensor in an intended direction of media travel thereacross, and a stabilizing layered structure between at least one of the magnetic shields and the sensor. The stabilizing layered structure has an antiferromagnetic layer, a first ferromagnetic layer adjacent the antiferromagnetic layer, and a second ferromagnetic layer. The antiferromagnetic layer pins a magnetization direction in the first ferromagnetic layer along an antiferromagnetic polarized direction of the antiferromagnetic layer. An antiparallel coupling layer is positioned between the ferromagnetic layers such that a magnetization direction in the second ferromagnetic layer is opposite the magnetization direction in the first ferromagnetic layer.