Abstract: A magnetoresistive sensor having an in stack bias layer with an engineered magnetic anisotropy in a direction parallel with the medium facing surface. The in-stack bias layer may be constructed of CoPt, CoPtCr or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to form anisotropic roughness in form of oriented ripples or facets. The anisotropic roughness induces a uniaxial magnetic anisotropy substantially parallel to the medium facing surface in the hard magnetic in-stack bias layer deposited thereover.

Abstract: A three terminal magnetic sensor (TTM) suitable for use in a magnetic head has a base region, a collector region, and an emitter region. A first barrier layer is located between the emitter region and the base region, and a second barrier layer is located between the collector region and the base region. An air bearing surface (ABS) sensing plane of the TTM is defined along sides of the base region, the collector region, and the emitter region. The base region includes a free layer structure, a pinned layer structure, a first non-magnetic spacer layer formed between the free layer structure and the pinned layer structure, an in-stack longitudinal biasing layer (LBL) structure which magnetically biases the free layer structure, and a second non-magnetic spacer layer formed between the free layer structure and the in-stack longitudinal biasing layer structure. In one variation, the layers in the base region are inverted.

Abstract: In one illustrative example, a three terminal magnetic sensor (TTM) suitable for use in a magnetic head has a base region, a collector region, and an emitter region. A first barrier layer is located between the emitter region and the base region, and a second barrier layer is located between the collector region and the base region. A sensing plane is defined along sides of the base region, the collector region, and the emitter region. The base region has a free layer structure, a pinned layer structure adjacent the first barrier layer, and a non-magnetic spacer layer located between the free layer structure and the pinned layer structure. The collector region comprises an in-stack longitudinal biasing layer (LBL) structure which magnetically biases the free layer structure, where the second barrier layer serves as a non-magnetic spacer layer for the in-stacking biasing layer structure. In one variation, the layers are inverted such that the emitter region has the in-stack LBL structure.

Abstract: In one illustrative example, a three terminal magnetic sensor (TTM) suitable for use in a magnetic head has a base region, a collector region, and an emitter region. A first barrier layer separates the emitter region from the base region, and a second barrier layer separates the collector region from the base region. A sensing plane is defined along sides of the base region, the collector region, and the emitter region. The base region consists of a free layer structure so as to have a relatively small thickness. A pinned layer structure is made part of the emitter region. An in-stack longitudinal biasing layer (LBL) structure which magnetically biases the free layer structure is made part of the collector region. In one variation, the emitter region has the in-stack LBL structure and the collector region has the pinned layer structure. The TTM may comprise a spin valve transistor (SVT), a magnetic tunnel transistor (MTT), or a double junction structure.

Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an improved antiparallel (AP) pinned structure. The AP-pinned structure has two ferromagnetic layers separated by a nonmagnetic antiparallel coupling (APC) layer and with their magnetization directions oriented antiparallel. One of the ferromagnetic layers in the AP-pinned structure is the reference layer in contact with the CPP-SV sensor's nonmagnetic electrically conducting spacer layer. In the improved AP-pinned structure each of the ferromagnetic layers has a thickness greater than 30 ?, preferably greater than approximately 50 ?, and the APC layer is either Ru or Ir with a thickness less than 7 ?, preferably about 5 ? or less. The ultrathin APC layer, especially if formed of iridium (Ir), provides significant coupling strength to allow the thick ferromagnetic layers to retain their magnetization directions in a stable antiparallel orientation.

Abstract: Current-perpendicular-to-the-plane (CPP), current-in-to-the-plane (CIP), and tunnel valve type sensors are provided having an antiparallel (AP) coupled free layer structure, an in-stack biasing structure which stabilizes the AP coupled free layer structure and a nonmagnetic spacer layer formed between the in-stack biasing layer and the AP coupled free layer structure. The AP coupled free layer structure has a first AP coupled free layer adjacent to the nonmagnetic spacer layer, a second AP coupled free layer, and an antiparallel coupling (APC) layer formed between the first and the second AP coupled free layers. The net moment of the AP coupled free layer structure has an antiparallel edge magnetostatic coupling with the in-stack biasing structure. At the same time, the first AP coupled free layer has an antiparallel exchange coupling with the second AP coupled free layer.

Abstract: A magnetoresistive sensor having an in stack bias structure. The sensor includes a bias spacer that allows biasing of free layer magnetic moment in a direction orthogonal to the magnetic moment of the biasing layer.

Abstract: A magnetically-coupled structure has two ferromagnetic layers with their in-plane magnetization directions coupled orthogonally across an electrically-conducting spacer layer that induces the direct orthogonal magnetic coupling. The structure has application for in-stack biasing in a current-perpendicular-to-the-plane (CPP) magnetoresistive sensor. One of the ferromagnetic layers of the structure is an antiparallel-pinned biasing layer and the other ferromagnetic layer is the sensor free layer. The antiparallel-pinned biasing layer has first and second ferromagnetic films separated by an antiferromagnetically-coupling film. An antiferromagnetic layer exchange-couples the first ferromagnetic film of the biasing layer to fix the net moment of the biasing layer parallel to the moment of the sensor pinned layer. This allows a single annealing step to be used to set the magnetization direction of the biasing and pinned layers.

Abstract: A magnetically-coupled structure has two ferromagnetic layers with their in-plane magnetization directions coupled orthogonally across an electrically-conducting spacer layer that induces the direct orthogonal magnetic coupling. The structure has application for in-stack biasing in a current-perpendicular-to-the-plane (CPP) magnetoresistive sensor. One of the ferromagnetic layers of the structure is a biasing ferromagnetic layer and the other ferromagnetic layer is the sensor free layer. An antiferromagnetic layer exchange-couples the biasing layer to fix its moment parallel to the moment of the sensor pinned layer. This allows a single annealing step to be used to set the magnetization direction of the biasing and pinned layers. The electrically-conducting spacer layer, the biasing layer and the antiferromagnetic layer that exchange-couples the biasing layer may all extend beyond the edges of the sensor stack.

Abstract: A semiconductor slider including an integral spin valve transistor (SVT) having a read width of 250 nm or less disposed on a monolithic semiconductor. substrate, useful in magnetic data storage applications. The monolithic slider may also include other magnetic and semiconductor transistor structures and is fabricated in a single process using standard thin-film processing steps. The SVT includes a sensor stack having a top surface and including a first ferromagnetic (FM) layer in contact with and forming a Schottky barrier at the monolithic semiconductor substrate, a FM shield layer disposed over the sensor stack and in electrical contact with the top surface thereof, a SVT emitter terminal coupled to the FM shield, a SVT collector terminal coupled to the substrate and a SVT base terminal coupled to the first FM layer. The sensor stack may include a spin valve (SV) stack or a tunnel valve (TV) stack, for example.

Abstract: A magnetic field sensor having a planar element made of a material formed by crystalline magnetoresistive thin layers with an anisotropy of resistivity in the planar element also having, in the planar element, two magnetization axes of different values. This sensor also has two electrical connections enabling, in the presence of an external magnetic field, the flow of a current in the element in a first direction that is not collinear with each of the axes of magnetization and two electrical connections enabling a measurement of voltage in a second direction transversal to the first direction. This sensor thus works by planar Hall effect.