摘要:
A magnetoresistive (MR) sensor or read head for a magnetic recording disk drive has multiple independent current-perpendicular-to-the-plane (CPP) MR sensing elements. The sensing elements are spaced-apart in the cross-track direction and separated by an insulating separation region so as to be capable of reading data from multiple data tracks on the disk. The sensing elements have independent CPP sense currents, each of which is directed to independent data detection electronics, respectively. Each sensing element comprises a stack of layers formed on a common electrically conducting base layer, which may be a bottom magnetic shield layer formed of electrically conducting magnetically permeable material. Each sensing element has a top electrical lead layer. A top magnetic shield layer is located above the sensing elements in contact with the top lead layers. The top shield layer is formed of soft magnetically permeable material, but is electrically insulating, so that the independent sense currents can be passed to the independent sensing elements.
摘要:
A hard disk drive (HDD) has a stack of disks mounted on a rotatable spindle with the disks being movable axially, i.e., in a direction parallel to the axis of rotation of the spindle. A disk separator is located inside the spindle and separates axially-adjacent disks in a pair to create an axial gap. Any pair of axially-adjacent disks can be separated so that different axial gaps are created. A single head-arm assembly with at least one and preferably two read write heads is movable axially so that it can be rotated by the rotary actuator into any one of the axial gaps. The read/write heads can thus access data on the disk surfaces in the axial gaps. When it is desired to have the disk separator create an new axial gap and thus a new pair of disk surfaces to be accessed, the actuator rotates the head-arm assembly away from the outer perimeters of the disks and moves the read/write heads onto a head support structure that supports the read/write heads off the disks.
摘要:
Magnetic memories and methods are disclosed. A magnetic memory as described herein includes a plurality of stacked data storage layers to form a three-dimensional magnetic memory. Bits may be written to a data storage layer in the form of magnetic domains. The bits can then be transferred between the stacked data storage layers by heating a neighboring data storage layer, which allows the magnetic fields from the magnetic domains to imprint the magnetic domains in the neighboring data storage layer. By imprinting the magnetic domains into the neighboring data storage layer, the bits are copied from one data storage layer to another.
摘要:
A laminated perpendicular magnetic recording medium has two recording layers (RL1 and RL2) that are separated and magnetically decoupled by a nonmagnetic spacer layer (SL). The SL has a thickness and composition to assure there is no antiferromagnetic or ferromagnetic coupling between RL1 and RL2. Thus in the presence of the write field, RL1 and RL2 respond independently and become oriented with the direction of the write field. Each RL is an “exchange-spring” type magnetic recording layer formed of two ferromagnetic layers (MAG1 and MAG2) that have substantially perpendicular magnetic anisotropy and are ferromagnetically exchange-coupled by a nonmagnetic or weakly ferromagnetic coupling layer (CL). The medium takes advantage of lamination to attain higher signal-to-noise ratio (SNR) yet has improved writability as a result of each RL being an exchange-spring type RL.
摘要:
A magnetic recording system uses a magnetic recording medium having a laminated magnetic structure with at least three magnetic layers, wherein the magnetic layers have decreasing intrinsic coercivity H0 with distance from the write head. The write field at the center of each magnetic layer is greater than that layer's H0. The magnetic layers have different compositions and/or thicknesses and thereby different values of H0. The alloys used in the middle and upper magnetic layers are relatively “high-moment” alloys that would not ordinarily be used in magnetic recording media because they have relatively low S0NR, but the overall S0NR of the laminated magnetic structure is improved because of the effect of lamination. The middle and upper magnetic layers can be made substantially thinner, which enables the magnetic layers to be located closer to the write head, thereby exposing each of the magnetic layers to a higher write field.
摘要:
A continuous-media perpendicular magnetic recording disk with an oxide-containing granular Co alloy recording layer (RL) having minimal grain size dispersion has an ordered nucleation layer (ONL) formed below RL. The ONL has ordered nucleation sites arranged in a generally repetitive pattern. The nucleation sites are generally surrounded by non-nucleation regions of a different material than the nucleation sites. The Co-alloy grains of the subsequently deposited RL grow on the nucleation sites and the oxide of the RL become generally segregated on the non-nucleation regions. The ordered nucleation sites may be formed of a Ru-containing material and the non-nucleation regions may be formed of an oxide. The ONL is formed by nanoimprint lithography, preferably by a master mold fabricated with a method using self-assembling block copolymers for creating periodic nanometer scale features.
摘要:
A magnetoresistive (MR) sensor or read head for a magnetic recording disk drive has multiple independent current-perpendicular-to-the-plane (CPP) MR sensing elements. The sensing elements are spaced-apart in the cross-track direction and separated by an insulating separation region so as to be capable of reading data from multiple data tracks on the disk. The sensing elements have independent CPP sense currents, each of which is directed to independent data detection electronics, respectively. Each sensing element comprises a stack of layers formed on a common electrically conducting base layer, which may be a bottom magnetic shield layer formed of electrically conducting magnetically permeable material. Each sensing element has a top electrical lead layer. A top magnetic shield layer is located above the sensing elements in contact with the top lead layers. The top shield layer is formed of soft magnetically permeable material, but is electrically insulating, so that the independent sense currents can be passed to the independent sensing elements.
摘要:
A hard disk drive (HDD) has a stack of disks mounted on a rotatable spindle with the disks being movable axially, i.e., in a direction parallel to the axis of rotation of the spindle. A disk separator is located inside the spindle and separates axially-adjacent disks in a pair to create an axial gap. Any pair of axially-adjacent disks can be separated so that different axial gaps are created. A single head-arm assembly with at least one and preferably two read write heads is movable axially so that it can be rotated by the rotary actuator into any one of the axial gaps. The read/write heads can thus access data on the disk surfaces in the axial gaps. When it is desired to have the disk separator create an new axial gap and thus a new pair of disk surfaces to be accessed, the actuator rotates the head-arm assembly away from the outer perimeters of the disks and moves the read/write heads onto a head support structure that supports the read/write heads off the disks.
摘要:
A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. In one embodiment of the invention, the incident beam is directed onto the surface to be inspected at an angle slightly offset from perpendicular so that the reflected beam is physically separated from the incident beam. The reflected beam is routed to a detector which converts the intensity of the reflected into an analog signal. The analog signal is sampled and digitized to generate pixel data stored in a buffer. Various analyses are performed on the data including calculating a rate of change in the pixel data. If the rate of change in the pixel data exceeds a selected threshold that indicates a possible defect if it occurs in the data area of the disk.
摘要:
A method for optically measuring at least one characteristic of a thin film on a reflecting substrate. A p-polarized beam of collimated light of known intensity is directed through an integrating sphere onto the film at substantially the Brewster's angle of the film. All the light is reflected into the sphere, including all diffusely reflected light as well as the light specularly reflected at a region inside the sphere where the specularly reflected light is incident. A reflective surface is provided for determining the thickness of the film as a function of the total intensity of light sensed within the sphere. An absorptive surface is provided at said region for absorbing the specularly reflected light for determining the porosity or surface roughness of the film based on the intensity of the diffused light sensed within the sphere not reflected from the substrate.