The present disclosure generally relates to read heads having dual free layer (DFL) sensors. The read head has a sensor disposed between two shields. The sensor is a DFL sensor and has a surface at the media facing surface (MFS). Recessed from the DFL sensor, and from the MFS, is a rear hard bias (RHB) structure. The RHB structure is disposed between the shields as well. In between the DFL sensor and the RHB structure is insulating material. The RHB is disposed on the insulating material. The RHB includes a RHB seed layer as well as a RHB bulk layer. The RHB bulk layer includes a first bulk layer and a second bulk layer, the first bulk layer having a different density relative to the second bulk layer.

A read head is disclosed wherein a Spin Hall Effect (SHE) layer is formed on a free layer (FL) in a sensor and between the FL and top shield (S2). Preferably, the sensor has a seed layer, an AP2 reference layer, antiferromagnetic coupling layer, AP1 reference layer, and a tunnel barrier sequentially formed on a bottom shield (S1). In a three terminal configuration, a first current flows between S1 and S2 such that the AP1 reference layer produces a first spin torque on the FL, and a second current flows across the SHE layer thereby generating a second spin torque on the FL that opposes the first spin torque. When the stripe heights of the FL and SHE layer are equal, a two terminal configuration is employed where a current flows between one side of the SHE layer to a center portion thereof and then to S1, or vice versa.

A read head is disclosed wherein a Spin Hall Effect (SHE) layer is formed on a free layer (FL) in a sensor and between the FL and top shield (S2). Preferably, the sensor has a seed layer, an AP2 reference layer, antiferromagnetic coupling layer, AP1 reference layer, and a tunnel barrier sequentially formed on a bottom shield (S1). When the stripe heights of the FL and SHE layer are equal, a two terminal configuration is employed where a current flows between one side of the SHE layer to a center portion thereof and then to S1, or vice versa. As a result, a second spin torque is generated by the SHE layer on the FL that opposes a first spin torque from the AP1 reference layer on the FL.

A magnetoresistive effect device includes a magnetoresistive effect element first and second ports, a signal line, an inductor, and a direct current input terminal. The first port, the magnetoresistive effect element, and the second port are connected in series in this order via the signal line. The inductor is connected to one of the signal line between the magnetoresistive effect element and the first port and the signal line between the magnetoresistive effect element and the second port and is capable of being connected to ground. The direct-current input terminal is connected to the other of the above signal lines. A closed circuit including the magnetoresistive effect element, the signal line, the inductor, the ground, and direct-current input terminal is capable of being formed. The magnetoresistive effect element is arranged so that direct current flows in a direction from a magnetization fixed layer to a magnetization free layer.

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 data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors and the head comprises a first read element and a second read element. When a first read command is received from a host to read a plurality of data sectors from the disk, the first read element is used to read a first data sector of the first read command, and when the first read element fails to recover the first data sector of the first read command, the second read element is used to read a second data sector of the first read command.

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.

A method of fabricating a TMR based magnetic sensor in a Wheatstone configuration includes conducting a first anneal of a magnetic tunnel junction (MTJ) and conducting a second anneal of the MTJ. The MTJ includes a first antiferromagnetic (AFM) pinning layer, a pinned layer over the first AFM pinning layer, an anti-parallel coupled layer over the pinned layer, a reference layer over the anti-parallel coupled layer, a barrier layer over the reference layer, a free layer over the barrier layer, and a second antiferromagnetic pinning layer over the free layer. The first anneal of the MTJ sets the first AFM pinning layer, the pinned layer, the free layer, and the second AFM pinning layer in a first magnetization direction. The second anneal of the MTJ resets the free layer and the second AFM pinning layer in a second magnetization direction. An operating field range of the TMR based magnetic sensor is over ±100 Oe.

A read head is disclosed wherein a Spin Hall Effect (SHE) layer is formed on a free layer (FL) in a sensor and between the FL and top shield (S2). Preferably, the sensor has a seed layer, an AP2 reference layer, antiferromagnetic coupling layer, AP1 reference layer, and a tunnel barrier sequentially formed on a bottom shield (S1). In a three terminal configuration, a first current flows between S1 and S2 such that the AP1 reference layer produces a first spin torque on the FL, and a second current flows across the SHE layer thereby generating a second spin torque on the FL that opposes the first spin torque. When the stripe heights of the FL and SHE layer are equal, a two terminal configuration is employed where a current flows between one side of the SHE layer to a center portion thereof and then to S1, or vice versa.

Embodiments of the present disclosure generally relate to a large field range TMR sensor of magnetic tunnel junctions (MTJs) with a free layer having an intrinsic anisotropy. In one embodiment, a tunnel magnetoresistive (TMR) based magnetic sensor in a Wheatstone configuration includes at least one MTJ. The MTJ includes a free layer having an intrinsic anisotropy produced by deposition at a high oblique angle from normal. Magnetic domain formations within the free layer can be further controlled by a pinned layer canted at an angle to the intrinsic anisotropy of the free layer, by a hard bias element, by shape anisotropy, or combinations thereof.