A magnetoresistance effect element and a Heusler alloy in which a state change due to annealing does not easily occur. The element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co.sub.2Fe.sub.αZ.sub.β is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Al, Si, Ga, Ge, and Sn, α and β satisfy 2.3≤α+β, α<β, and 0.5<α<1.9, and the substitution element is one or more elements selected from the group consisting of elements having a melting point higher than that of Fe among elements of Groups 4 to 10.

An exchange coupling film in which a magnetic field (Hex) at which the magnetization direction of a pinned magnetic layer is reversed is high, in which stability under high-temperature conditions is high, and which is excellent in strong-magnetic field resistance. The exchange coupling film includes an antiferromagnetic layer and a pinned magnetic layer including a ferromagnetic layer, the antiferromagnetic layer and the pinned magnetic layer being stacked together. The antiferromagnetic layer has a structure including a PtCr layer, a PtMn layer, and an IrMn layer stacked in this order. The IrMn layer is in contact with the pinned magnetic layer. The thickness of the PtMn layer is 12 Å or more, and the thickness of the IrMn layer is 6 Å. The sum of the thickness of the PtMn layer and the thickness of the IrMn layer is 20 Å or more.

A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a first layer and a second layer in order from the side closer to the non-magnetic layer, the first layer contains a crystallized Co-based Heusler alloy, at least a part of the second layer is crystallized, the second layer contains a ferromagnetic element, boron element and an additive element, and the additive element is any element selected from a group consisting of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt, and Au.

A method and system provide a magnetic read apparatus. The magnetic read apparatus includes a read sensor. The read sensor includes a pinning layer, a nonmagnetic insertion layer and a pinned layer. The nonmagnetic insertion layer has a location selected from a first location and a second location. The first location is between the pinned layer and the pinning layer. The second location is within the pinning layer.

According to one embodiment, a magnetic disk device includes a recording medium, a recording head including a main magnetic pole, a write shield magnetic pole, a coil, and a spin torque oscillator provided between the main magnetic pole and the write shield magnetic pole and a controller including a record current supply circuit and a drive current supply circuit. The controller executes a process of monitoring variation of a resistance value of the spin torque oscillator while increasing the record current in a state in which the spin torque oscillator is energized and detecting a record current value when the resistance value is increased most largely, and a process of setting the detected record current value to a lower limit of the record current supplied to the coil.

A spin valve magnetoresistance element has an even number of free layer structures for which half has an antiferromagnetic coupling and the other half has a ferromagnetic coupling with respect to associated pinned layers. The different couplings are the result of an even number different spacer layers having respective different thicknesses.

A method of forming a sub-structure, suitable for use as a hot seed in a perpendicular magnetic recording head, is described. A buffer layer of alumina with a thickness of 50-350 Angstroms is formed by atomic layer deposition as a write gap. Thereafter, one or more seed layers having a body-centered cubic (bcc) crystal structure may be deposited on the buffer layer. Finally, a magnetic film made of FeCo or FeNi with a coercivity of 60-110 Oe is deposited on the seed layer(s) by a physical vapor deposition (PVD) method at a rate of 0.48 to 3.6 Angstroms per second. The magnetic film is preferably annealed at 220° C. for 2 hours in a 250 Oe applied magnetic field.

A magnetoresistance element can have a substrate; a ferromagnetic seed layer consisting of a binary alloy of NiFe; and a first nonmagnetic spacer layer disposed under and directly adjacent to the ferromagnetic seed layer and proximate to the substrate, wherein the first nonmagnetic spacer layer is comprised of Ta or Ru. A method fabricating of fabricating a magnetoresistance element can include depositing a seed layer structure over a semiconductor substrate, wherein the depositing the seed layer structure includes depositing at least a ferromagnetic seed layer over the substrate. The method further can further include depositing a free layer structure over the seed layer structure, wherein the depositing the ferromagnetic seed layer comprises depositing the ferromagnetic seed layer in the presence of a motion along a predetermined direction and in the presence of a predetermined magnetic field having the same predetermined direction.

A double pinned magnetoresistance element has a temporary ferromagnetic layer, two PtMn antiferromagnetic pinning layers, and two associated synthetic antiferromagnetic (SAF) pinned layer structures, the temporary ferromagnetic layer operable to improve annealing of the two PtMn antiferromagnetic pinning layers and the two associated SAFs to two different magnetic directions that are a relative ninety degrees apart.

A magnetic read element having an additional magnetic layer, “a floating magnetic shield”, formed as a part of a capping structure of a magnetoresistive element. The capping structure is formed over the magnetic free layer and includes a magnetic layer that is located between first and second non-magnetic layers. The magnetic layer can advantageously he formed with a high magnetic permeability for increased signal amplitude and increased signal resolution. In addition, because the magnetic layer of the capping layer structure acts as a magnetic shield, it can reduce effective magnetic gap spacing for increased signal resolution.