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 method of sensing molecules using a detection device, the detection device comprising a plurality of magnetoresistive (MR) sensors and at least one fluidic channel, comprising adding a plurality of molecules to be detected to the at least one fluidic channel, wherein at least some of the plurality of molecules to be detected are coupled to respective magnetic nanoparticles (MNPs), detecting a characteristic of a magnetic noise of a first MR sensor of the plurality of MR sensors, wherein the characteristic of the magnetic noise is influenced by a presence of one or more MNPs in a vicinity of the first MR sensor, and determining, based on the detected characteristic, whether the first MR sensor detected the presence of one or more MNPs in the vicinity of the first MR sensor.

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.

The present disclosure generally relates to magnetic media devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The recording head includes a main pole, a trailing shield hot seed layer, a spin Hall layer disposed between the main pole and the trailing shield hot seed layer, and a spin-torque layer disposed between the main pole and the trailing shield hot seed layer. Spin-orbit torque (SOT) is generated from the spin Hall layer. The spin-torque layer magnetization switching or precession is induced by the SOT. The SOT based head reduces the switching current and the V.sub.jump due to higher spin polarization ratio, which improves energy efficiency. In addition, the spin Hall layer and the spin-torque layer are easier to form compared to the conventional pseudo spin-valve structure.

The present disclosure generally related to a two dimensional magnetic recording (TDMR) read head having a magnetic tunnel junction (MTJ). Both the upper reader and the lower reader have a dual free layer (DFL) MTJ structure between two shields. A synthetic antiferromagnetic (SAF) soft bias structure bounds the MTJ, and a rear hard bias (RHB) structure is disposed behind the MTJ. The DFL MTJ decreases the distance between the upper and lower reader and hence, improves the area density capacity (ADC). Additionally, the SAF soft bias structures and the rear head bias structure cause the dual free layer MTJ to have a scissor state magnetic moment at the media facing surface (MFS).

A Wheatstone bridge array comprising a tunneling magnetoresistive (TMR) sensor and a method for manufacturing is disclosed. The bottom lead for the TMR sensor has a very small surface roughness due to not only chemical mechanical planarization (CMP) but also due to forming the bottom lead from multiple layers. The multiple layers include at least a bottom first metal layer and a top second metal layer disposed on the first metal layer. The second metal layer generally has a lower surface roughness than the first metal layer. Additionally, the second metal layer has a slower polishing rate. Therefore, not only does the second metal layer reduce the surface roughness simply be being present, but the slower polishing rate enables the top second metal film to be polished to a very fine surface roughness of less than or equal to ˜2 Angstroms.

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.

A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, the tunnel barrier layer is expressed by a chemical formula of AB.sub.2O.sub.x, and has a spinel structure in which cations are arranged in a disordered manner, A represents a divalent cation that is either Mg or Zn, and B represents a trivalent cation that includes a plurality of elements selected from the group consisting of Al, Ga, and In.

A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and the tunnel barrier layer has a spinel structure in which cations are disordered, and contains a divalent cation of a non-magnetic element, a trivalent cation of a non-magnetic element, oxygen, and one of nitrogen and fluorine.

A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer. The tunnel barrier layer is a stacked body including one or more first oxide layers having a spinel structure and one or more second oxide layers having a spinel structure with a composition which is different from a composition of the first oxide layer.