摘要:
A flux guided magnetic tunnel junction head includes a ferromagnetic pinned layer having an active region with a front edge recessed from a sensing surface, and a non-active region located between the sensing surface and the active region. The non-active region of the ferromagnetic pinned layer is rendered substantially non-conducting by chemically processing the ferromagnetic material of the ferromagnetic pinned layer in this region. The flux guided MTJ head also includes a ferromagnetic free layer having a front edge substantially coplanar with a sensing surface. The ferromagnetic free layer can function as a flux guide to direct magnetic flux from a recording medium to the tunnel junction. The location of the front edge of the ferromagnetic pinned layer prevents any shorting of the flux guided MTJ head occurring when the head is lapped at the sensing surface.
摘要:
A magnetoresistive read sensor incorporates a multilayer sensing element formed of one or more magnetoresistive elements in a planar array, each magnetoresistive element having a multilayer structure of at least two ferromagnetic layers separated by a nonmagnetic layer. The ferromagnetic layers are coupled antiferromagnetically by magnetostatic coupling at opposing edges of the ferromagnetic layers. A bias layer separated from the magnetoresistive sensing element by a spacer layer provides a magnetic field to bias the magnetoresistive sensing element at a desired non-signal point for linear response. The magnetoresistive sensing element is formed by alternatively depositing layers of ferromagnetic material and layers of nonmagnetic material on a substrate and then patterning the resulting structure using photolithographic techniques to provide a planar array of magnetoresistive elements. A conductive layer is deposited over the array filling in the spaces separating the magnetoresistive elements to provide electrical conductivity between the elements in the plane of the structure.
摘要:
A magnetoresistive (MR) read transducer assembly in which the thin film MR layer is longitudinally biased only in the end regions by exchange bias developed by a thin film of antiferromagnetic material that is deposited in direct contact with the MR layer in the end regions. The longitudinal bias is of a level sufficient to maintain the end regions of the MR layer in a single domain state and thereby induce a single domain state in the central region of the MR layer. Transverse bias is produced within the central region of the MR layer of a level sufficient to maintain that region of the MR layer in a linear response mode. Spaced conductive elements are connected to the MR layer within the central region to define a detection region so that signal output means connected to the conductive elements can determine the resistance changes in the detection region of the MR layer as a function of the fields which are intercepted by the MR layer.
摘要:
A current-perpendicular-to-the-plane (CPP) magnetoresistive sensor or read head has a magnetic shield geometry that covers the side walls of the sensor structure to prevent side reading caused by magnetic flux entering from adjacent data tracks. The shield geometry includes a bottom shield with a substantially planar surface and a specially shaped top shield. The top shield has substantially vertical portions generally parallel to the side walls of the sensor structure, a horizontal top portion over the trackwidth region of the sensor, and horizontal side portions formed over the portions of the bottom shield on either side of the sensor structure. The insulating gap material that separates the bottom and top shields is in contact with the horizontal portions of the bottom shield and the side walls of the sensor structure.
摘要:
An MR read transducer having passive end regions separated by a central active region comprises an MR layer made from a material having a low uniaxial magnetic anisotropy. A soft magnetic bias layer is adjacent to but spaced from the MR layer in the central region only, and the soft magnetic bias layer is made from a material having a high uniaxial magnetic anisotropy. A longitudinal bias is produced directly in each of the end regions only, and the means for producing the longitudinal bias comprise a layer made from a material having a high uniaxial magnetic anisotropy. Control of the uniaxial anisotropy can be achieved by choosing materials of appropriate magnetostriction or intrinsic uniaxial anisotropy.
摘要:
A magnetoresistive (MR) read transducer in which a layered structure comprising an MR layer, an antiferromagnetic material in direct contact with the MR layer and a thin layer of interdiffusion material in contact with the layer of antiferromagnetic material is subjected to a heating process to a temperature within a chosen temperature for a chosen time to form a magnetic interface between the antiferromagnetic material the MR layer. The magnetic interface produces a high level of exchange bias with the MR layer.
摘要:
A rotary actuator disk drive uses substantially identical dual-element inductive write/magnetoresistive read transducers for both the top and bottom disk surfaces. There is no requirement that the read elements be mechanically offset from the write elements, as is typically the case in rotary actuator disk drives due to the head-to-track skew caused by the inherent nonlinear path of the heads across the data tracks. The transducers are supported on the trailing ends of the head carriers in such a manner that the geometric centers of the read and write elements are aligned without any mechanical offset. Sense currents of opposite polarity are provided to the magnetoresisitve read elements adjacent the top and bottom disk surfaces to shift the magnetic centers of the top and bottom read elements in opposite directions relative to their geometric centers. The amount and direction of the magnetic shift is such that the read elements are effectively offset from their respective write elements so that the skew caused by the rotary actuator has minimal effect on alignment of the read and write elements with the data tracks.
摘要:
A merged MR head is provided which has vertically aligned sidewalls so as to minimize side-fringing and improve off-track performance. The bottom pole piece P1, which comprises the second shield layer S2 of the read head, has a pedestal pole tip with a short length dimension. A pedestal pole tip with a length as short as two times the length of the gap layer G optimally minimizes the sidewriting and improves off-track performance. The bottom pole tip structure of the write head is constructed by ion beam milling using the top pole tip structure as a mask. The ion beam milling is directed at an angle to the sidewalls of the top pole tip structure which causes the bottom pole tip structure to be milled with sidewalls which align with the top pole tip structure. The ion beam milling can comprise two angled beams, either sequentially or simultaneously, the first beam performing primarily a cutting operation and some clean up work while the second beam primarily conducts clean up work of the redeposition of the debris caused by the cutting. In another embodiment, a single angled ion beam can be employed, provided its angle is within a particular range.
摘要:
A method and device for use in measurement and compensation of nonlinear bitshift in nonlinear communication media such as magnetic and optical recording devices. The method and device are based on special bit patterns constructed to eliminate at least one harmonic of the fundamental frequency of the data pattern if all bits are communicated without any nonlinear bitshift. The presence of nonlinear bitshift is manifested by the appearance of the harmonic. By measuring the magnitude of the harmonic, the amount of nonlinear bitshift is determined, and compensation adjustment is then used to offset its effect on the data detection scheme.
摘要:
A method for producing a magnetic structure, such as a thin film magnetic head, in which the magnetic and electrical characteristics of magnetic material are tailored to produce magnetic and electrical characteristics in selected localized areas of the magnetic material. In a specific embodiment, the structure comprises a layer of magnetic material having an overlayer and an underlayer, and the magnetic characteristics of the material are modified by rapid thermal annealing.