Abstract: A two-dimensional magnetic recording (TDMR) read head has upper and lower read sensors wherein the lower read sensor has its magnetization biased by side shields of soft magnetic material. The center shield between the lower and upper sensors may be an antiparallel structure (APS) with two ferromagnetic layers separated by an antiparallel coupling (APC) layer. The center shield has a central region and two side regions, but there is no antiferromagnetic (AF) layer in the central region. Instead the two side regions of the upper ferromagnetic layer in the APS are pinned by AF tab layers that are electrically isolated from the upper sensor. The upper ferromagnetic layer and the APC layer in the APS may also be located only in the side regions. The thickness of the center shield can thus be made thinner, which reduces the free layer to free layer spacing.

Abstract: The present invention generally relates to a write head pole laminate structure. The write head pole structure can include multiple multi-layer magnetic structures that are separated by a non-magnetic material that is amorphous or microcrystalline. Each multi-layer magnetic structure includes one or more first magnetic layers that are spaced from one or more second magnetic layers by a non-magnetic layer such that the one or more first magnetic layers are substantially identical to the one or more second magnetic layers. In such a design, the one or more second magnetic layers are antiparallel to the one or more first magnetic layers so that a zero total net magnetic moment is present for the multi-layer magnetic structure when current is removed from the write head pole.

Abstract: A two-dimensional magnetic recording (TDMR) read head structure has the lower read sensor free layer magnetization biased by side shields of soft magnetic material. A center shield between the lower and upper sensors is an antiparallel coupled magnetic structure, i.e., first and second ferromagnetic layers separated by an antiparallel coupling (APC) layer. The first ferromagnetic layer is ferromagnetically exchange coupled to the side shields of the lower sensor to stabilize the magnetization of the lower sensor's free layer. The first ferromagnetic layer of the center shield is a multilayer of a lower NiFe layer and an upper CoFeB alloy layer inserted below the APC layer. The CoFeB alloy insertion layer increases the antiparallel coupling of the first and second ferromagnetic layers of the center shield after two orthogonal anneals so that the magnetization of the first ferromagnetic layer is aligned parallel to the air-bearing surface (ABS) of the TDMR structure.

Abstract: A perpendicular magnetic recording write head has a main pole that is typically CoFe electroplated into a generally trapezoidal shaped alumina trench. A metallic side gap layer is deposited into the alumina trench to adjust the trench width to the desired main pole dimension. A nonmagnetic metallic amorphous underlayer, preferably an amorphous NiTa alloy or an amorphous NiNb alloy, is then deposited on the side gap layer. A pole seed layer, such as a NiCr/CoFe bilayer, is deposited into the trench onto the metallic amorphous underlayer prior to electroplating the CoFe main pole. The metallic amorphous underlayer serves to reset the growth between the side gap layer and the NiCr/CoFe pole seed layer. The metallic amorphous underlayer does not insulate the electroplating CoFe layer from the metallic side gap layer, which allows for better current conduction normal to the layers, resulting in a main pole with improved magnetic properties.

Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has both side shields and an antiparallel structure (APS) top shield. The APS top shield is an antiferromagnetically exchange-coupled top shield that includes an antiparallel (AP) coupled structure and an antiferromagnetic (AF) layer which permits the use of the desired NiFex (x is between 15 and 25 atomic percent) material for the side shields. The APS top shield includes lower and upper ferromagnetic layers with respective antiparallel magnetizations. The antiparallel coupling structure between the two ferromagnetic layers consists of the antiparallel coupling (APC) film, which is typically Ru, Ir or Cr, and one and only one interface film of Co or CoFe. The APS top shield with one and only one Co or CoFe interface film enables the material of the side shields to be formed of the preferred NiFex (x is between 15 and 25 atomic percent) material without over-stabilization of the free layer.

Abstract: Methods and apparatus provide magnetoresistance sensors. A tunneling magnetoresistance (TMR) sensor may include configurations that are arranged as a top TMR stack. One of two antiparallel layers of pinned layers within the TMR stack may be subdivided by a spacer layer. Tantalum may form the spacer layer that is inserted in a reference layer, which is one of the pinned layers and is located between a barrier layer and an antiparallel coupling layer that enables antiparallel coupling between the reference layer and a keeper layer of the pinned layers. The barrier layer deposited on a free layer of the TMR stacks separates the pinned layers from the free layer such that TMR effects are detectable with the sensors.

Abstract: A hard magnet biasing structure for a CPP-GMR or CPP-TMR read head for a magnetic recording disk drive is located between the two sensor shields and abutting the side edges of the sensor free layer. The biasing structure includes a crystalline MgO insulating layer on the lower shield and the side edges of the free layer, a seed layer of either Ir or Ru on and in contact with the MgO layer, a layer of at least partially chemically-ordered ferromagnetic FePt alloy hard bias layer on the seed layer, and a capping layer on the FePt alloy hard bias layer. The MgO layer may be a single layer on and in contact with the side edges of the free layer, or an upper layer on and in contact with a base insulating layer selected from an aluminum oxide, a tantalum oxide, a titanium oxide, and a silicon nitride.

Abstract: A current-perpendicular-to-the-plane magnetoresistive sensor structure includes at least an improved top shield structure and optionally also a similar bottom shield structure. The top shield structure includes an antiparallel structure (APS) of two ferromagnetic films and a nonmagnetic antiparallel coupling (APC) film between them. The APC film induces antiferromagnetic (AF) coupling between the two ferromagnetic films so that they have their respective magnetizations oriented antiparallel. An important aspect of the APS is that there is no antiferromagnetic layer adjacent the upper ferromagnetic film, so that the upper ferromagnetic film does not have its magnetization pinned by an antiferromagnetic layer. An electroplated shield layer is formed above the APS.

Abstract: A current-perpendicular-to-the-plane magnetoresistive sensor has an exchange-coupled side shield structure on each of two side regions of the sensor and an exchange-coupled top shield structure on the sensor and the two exchange-coupled side shield structures. Each exchange-coupled structure comprises an antiferromagnetic layer and a shield of soft magnetically permeable material exchange-coupled with the antiferromagnetic layer. Each side shield and the top shield has its magnetization oriented generally parallel to the sensor front edge and generally parallel to the plane of the sensor's free ferromagnetic layer. The shields in each exchange-coupled side shield structure and the exchange-coupled top shield structure may be an antiparallel coupled structure of two magnetically permeable films separated by a nonmagnetic coupling film.

Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has an improved seed layer structure for the ferromagnetic hard (high coercivity) bias layer that is used to longitudinally bias the sensor's free ferromagnetic layer. The seed layer structure is a trilayer consisting of a first seed layer of tantalum (Ta), a second seed layer of one or both titanium (Ti) and Ti-oxide on and in contact with the Ta layer, and a third seed layer of tungsten (W) on and in contact with the second seed layer.

Abstract: A method in one embodiment includes forming a first layer of magnesium above at least one of a free layer and a reference layer; exposing the first layer of magnesium to an oxidizing environment for causing oxidation of the first layer of magnesium; forming a second layer of magnesium above the oxidized first layer of magnesium; and exposing the second layer of magnesium to the oxidizing environment for causing oxidation of the second layer of magnesium. A system in one embodiment includes a free layer; and a tunnel barrier layer having microstructure and composition characteristic of in situ natural oxidation of magnesium. Additional systems and methods are also presented.

Abstract: A perpendicular magnetic recording write head has an improved antiparallel-coupled laminated main pole (MP) with a tapered trailing edge. The laminated MP has three ferromagnetic layers and two non-magnetic antiparallel-coupling (APC) layers. A first ferromagnetic layer (FM1) has a thickness T1 and a planar end face at the air-bearing surface (ABS). A second ferromagnetic layer (FM2) has a total thickness T2 and includes a first portion with a thickness T4 that has an end face coplanar with the end face of FM1 and a second portion with a tapered end face. A first APC layer separates FM1 and FM2. A third ferromagnetic layer (FM3) has a thickness T3 and a tapered end face that is coplanar with the tapered end face of FM2. A second APC layer separates FM2 and FM3. The net flux is minimized at both the ABS and at MP cross-sections recessed from the ABS.

Abstract: According to one embodiment, a method for forming at least a portion of a magnetic head includes forming a keeper layer, forming a reference layer, and forming an AFM coupling layer which is positioned between the keeper layer and the reference layer. In addition, forming the reference layer includes forming a layer of CoFe, depositing a layer of CoFeHf which is about 20 atomic % Hf, and depositing a layer of CoFeB such that the layers of CoFeHf and CoFeB are directly adjacent and a ratio of respective physical thicknesses of CoFeHf to CoFeB is less than about 0.66. Other embodiments are also included such as a magnetic head and additional methods for forming at least a portion of a magnetic head.

Abstract: A hard magnet biasing structure for a CPP-GMR or CPP-TMR read head for a magnetic recording disk drive is located between the two sensor shields and abutting the side edges of the sensor free layer. An insulating layer is located between the biasing structure and the lower shield and the side edges of the free layer. The biasing structure includes a seed layer of either Ir or Ru, a layer of ferromagnetic chemically-ordered FePt alloy hard bias layer on the seed layer, and a Ru or Ru/Ir capping layer on the FePt alloy hard bias layer. The FePt alloy has a face-centered-tetragonal structure with its c-axis generally in the plane of the layer. The relatively thin seed layer and capping layer allow the biasing structure to be made very thin while still permitting the FePt alloy hard bias layer to have high coercivity (Hc), a high remanent magnetization-thickness product (Mrt) and a high squareness (S=Mrt/Ms).

Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has a dual composition hard bias layer structure that is used to longitudinally bias the sensor's free ferromagnetic layer. The dual composition hard bias layer structure is composed of first layer of CoPt, having high anisotropy compared to the second layer. The second layer, composed of CoFe, has a higher magnetization compared to the first layer. The resulting dual hard bias layer structure exhibits high values of coercivity and squareness while maintaining a reduced sensor thickness compared to sensors of the prior art.

Abstract: The present invention generally relates to a write head pole laminate structure. The write head pole structure can include multiple multi-layer magnetic structures that are separated by a non-magnetic material that is amorphous or microcrystalline. Each multi-layer magnetic structure includes one or more first magnetic layers that are spaced from one or more second magnetic layers by a non-magnetic layer such that the one or more first magnetic layers are substantially identical to the one or more second magnetic layers. In such a design, the one or more second magnetic layers are antiparallel to the one or more first magnetic layers so that a zero total net magnetic moment is present for the multi-layer magnetic structure when current is removed from the write head pole.

Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has an improved seed layer structure for the ferromagnetic hard (high coercivity) bias layer that is used to longitudinally bias the sensor's free ferromagnetic layer. The seed layer structure is a trilayer consisting of a first seed layer of tantalum (Ta), a second seed layer of one or both titanium (Ti) and Ti-oxide on and in contact with the Ta layer, and a third seed layer of tungsten (W) on and in contact with the second seed layer.

Abstract: A perpendicular magnetic recording write head has an improved antiferromagnetically-coupled laminated main pole (MP) formed on a substrate. The MP has two ferromagnetic multilayers, each comprising at least one FeCo/NiFe/FeCo ferromagnetic trilayer, antiferromagnetically coupled across an antiferromagnetically coupling (AFC) film consisting essentially of ruthenium (Ru). The MP has a NiFe layer directly above the AFC film, on the side of the AFC film opposite the side facing the substrate, and in contact with the Ru AFC film and the lower FeCo layer of the upper multilayer. There is no NiFe layer directly below the Ru AFC film so the side of the AFC film facing the substrate is in direct contact with the upper FeCo layer of the lower multilayer.

Abstract: A magnetoresistive sensor having an antiparallel coupled pinned layer structure including an AP1 layer and an AP2 layer. The AP2 layer includes two ferromagnetic layers AP2(a) and AP2(b), and a separation layer sandwiched therebetween. The AP2(a) layer is significantly larger than the AP2(b) layer, which results in strong pinning, while the separation layer provides increased TMR and reduced RA.

Abstract: A perpendicular magnetic recording write head has an improved antiferromagnetically-coupled laminated main pole (MP) formed on a substrate. The MP has two ferromagnetic multilayers, each comprising at least one FeCo/NiFe/FeCo ferromagnetic trilayer, antiferromagnetically coupled across an antiferromagnetically coupling (AFC) film consisting essentially of ruthenium (Ru). The MP has a NiFe layer directly above the AFC film, on the side of the AFC film opposite the side facing the substrate, and in contact with the Ru AFC film and the lower FeCo layer of the upper multilayer. There is no NiFe layer directly below the Ru AFC film so the side of the AFC film facing the substrate is in direct contact with the upper FeCo layer of the lower multilayer.