Abstract: A multilayered spin valve read head including an antiferromagnetic pinning layer and a ferromagnetic pinned layer which can maintain a high pinning field between the layers while minimizing the coercivity of the pinning layer. The apparatus and method of the invention comprise placing a thin discontinuous nonmagnetic interlayer such as Cu between the antiferromagnetic and the ferromagnetic layers.

Abstract: A spin valve magnetoresistive (SVMR) sensor uses a laminated antiparallel (AP) pinned layer in combination with an improved antiferromagnetic (AF) exchange biasing layer. The pinned layer comprises two ferromagnetic films separated by a nonmagnetic coupling film such that the magnetizations of the two ferromagnetic films are strongly coupled together antiferromagnetically in an antiparallel orientation. This laminated AP pinned layer is magnetically rigid in the small field excitations required to rotate the SVMR sensor's free layer. When the magnetic moments of the two ferromagnetic layers in this AP pinned layer are nearly the same, the net magnetic moment of the pinned layer is small. However, the exchange field is correspondingly large because it is inversely proportional to the net magnetic moment. The laminated AP pinned layer has its magnetization fixed or pinned by an AF material that is highly corrosion resistant but that has an exchange anisotropy too low to be usable in conventional SVMR sensors.

Abstract: First and second shield layers of a read head are constructed of a lamination of NiMn and Fe-based layers to improve the performance of the shield layers when they are subjected to high external fields, such as from the pole tips of a write head combined therewith. Without lamination with one or more NiMn layers, many shield materials do not return to the same domain configuration after excitation from an external field. The result is that the Fe-based material assumes a different domain configuration after each excitation which changes the bias point of the MR sensor of the read head. By laminating with NiMn, the uniaxial anisotropy of the material can be increased to provide uniform domain configuration and exchange pinning between shield material NiMn returns the material to the same configuration after each external field excitation.

Abstract: An improved spin valve (SV) magnetoresistive element has its free ferromagnetic layer in the form of a central active region with defined edges and end regions that are contiguous with and abut the edges of the central active region. A layer of antiferromagnetic material, preferably a nickel-manganese (Ni--Mn) alloy, is formed on and in contact with the ferromagnetic material in the end regions for exchange coupling with the end regions to provide them with a longitudinal bias of their magnetizations. The pinned ferromagnetic layer in the SV element is pinned by exchange coupling with a different layer of antiferromagnetic material, preferably an iron-manganese (Fe--Mn) alloy. This material has a substantially different Neel temperature from that of the antiferromagnetic material on the end regions.

Abstract: First and second shield layers of a read head are constructed of a lamination of NiMn and Fe-based layers to improve the performance of the shield layers when they are subjected to high external fields, such as from the pole tips of a write head combined therewith. Without lamination with one or more NiMn layers, many shield materials do not return to the same domain configuration after excitation from an external field. The result is that the Fe-based material assumes a different domain configuration after each excitation which changes the bias point of the MR sensor of the read head. By laminating with NiMn, the uniaxial anisotropy of the material can be increased to provide uniform domain configuration and exchange pinning between shield material NiMn returns the material to the same configuration after each external field excitation.

Abstract: In a magnetoresistive (MR) read sensor in which the MR layer is transversely biased by a soft magnetic layer separated from the MR layer by a nonmagnetic spacer layer an antiferromagnetic stabilization layer of NiO provides a stabilizing exchange-coupled magnetic field to the transverse bias layer insuring that the transverse bias layer is fully saturated in a preferred direction during sensor operation.

Abstract: In a magnetoresistive (MR) read sensor in which the MR layer is transversely biased by a soft magnetic layer separated from the MR layer by a nonmagnetic spacer layer an antiferromagnetic stabilization layer of NiO provides a stabilizing exchange-coupled magnetic field to the transverse bias layer insuring that the transverse bias layer is fully saturated in a preferred direction during sensor operation.

Abstract: A magnetic disk storage system wherein a magnetic includes a magnetoresistive sensor is described. The MR sensor comprises a sputtered layer of ferromagnetic material and a sputtered layer of antiferromagnetic nickel-manganese (Ni-Mn) to provide an exchange coupled longitudinal bias field in the MR element. The antiferromagnetic layer overlays the MR layer and may be patterned to provide the longitudinal bias field only in the end regions of the MR layer. Alternatively, the antiferromagnetic layer can underlay the MR layer with a Zr underlayer to enhance the exchange-coupled field. As initially deposited, the Ni-Mn layer has a face-centered-cubic crystalline structure and exhibits little or no exchange-coupled field. After one annealing cycle at a relatively low temperature, the Ni-Mn layer crystalline structure is face-centered-tetragonal and exhibits increased crystallographic ordering and provides sufficient exchange coupling for the MR element to operate.

Abstract: A magnetoresistive (MR) sensor comprising a sputtered layer of ferromagnetic material and a sputtered layer of antiferromagnetic nickel-manganese (Ni-Mn) to provide an exchange coupled longitudinal bias field in the MR element is described. The antiferromagnetic layer overlays the MR layer and may be patterned to provide the longitudinal bias field only in the end regions of the MR layer. Alternatively, the antiferromagnetic layer can underlay the MR layer with a Zr underlayer to enhance the exchange-coupled field. As initially deposited, the Ni-Mn layer is face-centered-cubic and exhibits little or no exchange-coupled field. After one annealing cycle at a relatively low temperature, the Ni-Mn layer is face-centered-tetragonal and exhibits increased crystallographic ordering and provides sufficient exchange coupling for the MR element to operate. Addition of chromium to the Ni-Mn alloy provides increased corrosion resistance.

Abstract: A magnetoresistive (MR) sensor comprising a sputtered layer of ferromagnetic material and a sputtered layer of antiferromagnetic nickel-manganese (Ni-Mn) to provide an exchange coupled longitudinal bias field in the MR element is described. The antiferromagnetic layer overlays the MR layer and may be patterned to provide the longitudinal bias field only in the end regions of the MR layer. Alternatively, the antiferromagnetic layer can underlay the MR layer with a Zr underlayer to enhance the exchange-coupled field. As initially deposited, the Ni-Mn layer is face-centered-cubic and exhibits little or no exchange-coupled field. After one annealing cycle at a relatively low temperature, the Ni-Mn layer is face-centered-tetragonal and exhibits increased crystallographic ordering and provides sufficient exchange coupling for the MR element to operate. Addition of chromium to the Ni-Mn alloy provides increased corrosion resistance.