Abstract: A method, apparatus, and system are provided for implementing touchdown measurement using thermal and voltage actuation for hard disk drives (HDDs). The touchdown measurement uses a constant power applied to a thermal flyheight control (TFC) and an electrostatic voltage bias pulse is applied between the slider body and the disk to actuate the slider into contact with the disk.

Abstract: Embodiments of the present invention provide a simplified authentication transaction for reconnecting a storage device to a host apparatus that has completed authentication in the past. According to one embodiment, an authentication log is recorded in the host. Plural units of this log information are recorded in the storage device. At the time of transferring a content decryption key and usage rules between the host and the storage device, the decryption key and usage rules are recorded into the host as a log for the transfer. The used authentication log is recorded into the storage device as RAPDI. If RAPDI indicates the authentication log in the simplified authentication transaction, recovery transaction is permitted. The host device deletes/invalidates or holds the log for the transfer in accordance with non-permission/permission. In the case of permission, the key and usage rules are recovered by using a log for the transfer prior to the simplified authentication transaction.

Abstract: A magnetic read head configured for two dimensional magnetic recording and having asymmetrical secondary read elements. The magnetic read head includes a primary read element configured to read a data track (i.e. n data track) and first and second secondary read elements located over adjacent data tracks (i.e. n+1, n?1 data track) at either side of the data track to be read. The secondary read element have asymmetrical off track amplitude profiles, preferably such that they each have a steep amplitude profile at the outer side and a broader cross-track amplitude profile at their inner sides. This allows the secondary read elements to detect signals of the adjacent data track (so that those signals can be subtracted out of the signal from the primary reader) without the secondary read elements also picking up further adjacent data tracks (i.e. n+2, n?2).

Abstract: A technique implemented by a processor may include controlling a write head to write data to at least one partition of a data track of a magnetic data storage medium. The data track may include a plurality of partitions. The technique also may include determining, for each partition of the at least one partition, whether the partition has been previously written to by inspecting a partition overlap register associated with the data track. The partition overlap register stores a respective entry for each partition indicating whether the partition has been previously written to. The technique also may include, in response to determining that at least one respective partition of the at least one partition has been previously written to, incrementing a damage counter of at least one adjacent track and resetting each entry of the partition overlap register to indicate that each respective partition has not been previously written to.

Abstract: In one embodiment, a device includes a near-field light transducer having multiple apexes including a trailing-side apex positioned on a trailing side of the near-field light transducer. The device also includes a first material positioned near the trailing-side apex of the near-field light transducer, and a second material positioned near another apex of the near-field light transducer. The first material is physically characterized as etching more slowly than the second material.

Abstract: A lubricant according to one embodiment includes a cyclophosphazene according to chemical formula 1,

Abstract: The present disclosure relates to a method for fabricating an ion-implanted bit-patterned medium. The method includes providing a medium, the medium having a magnetic layer and a substrate and the magnetic layer includes migrating components. The method further includes forming a patterned mask layer on the surface of the magnetic layer and then ion-implanting the medium through the patterned mask layer, wherein the exposed portions of the magnetic layer comprise trench regions, the covered portions of the magnetic layer comprise island regions, and the transition areas between the trench regions and the island regions comprise boundary regions, wherein the island regions have more favorable magnetic properties than the trench regions. The method also includes annealing the medium, wherein the migrating components diffuse from inside the island regions towards the trench regions.

Abstract: An embodiment of the present invention implements some or all major servo subfunctions for a storage device in integrated servo fields comprising sequences of encoded bits having selected mathematical properties. The integrated servo field is composed of a number of encoded sequences, which are members of a selected sequence set that is constrained to preferably provide some or all of the following functions: the Servo Track Mark (STM), the Position Error Signal (PES) and location information such as the track-ID. The juxtaposition of sequences in the servo wedges is additionally constrained to increase the detectability of the contribution of adjacent sequences in the read signal. The integrated servo fields can provide a Position Error Signal (PES) in relation to the center of a data track through the amplitude of the signal read for adjacent sequences.

Abstract: A method using directed self-assembly of block copolymers (BCPs) for making an imprint template has the required patterns for both the features in the template's active area and the optically-detectable alignment marks in the template's non-active area. A chemical contrast pattern defined by a lithographic technique forms patterns of lines in both the active area and non-active area, as well as patterns of featureless gap regions in the non-active area. The pattern of lines has the BCP components aligned as lamellae perpendicular to the substrate, while the pattern of featureless gap regions has the BCP components aligned as lamellae parallel to the substrate. The patterns of lines and featureless gap regions in the non-active area define the optically detectable alignment marks. One of the BCP components is removed, leaving the other BCP component as an etch mask to fabricate the imprint template.

Abstract: A magnetoresistive sensing system includes a current-perpendicular-to-the-plane magnetoresistive (CPP-MR) read head and adjustable biasing circuitry connected to the read head for adjusting the relative magnetizations of one or more of the ferromagnetic layers in the read head. The biasing circuitry generates a bias current in the read head that generates a bias-adjusting magnetic field that acts on one or more of the ferromagnetic layers. For a conventional read head, the bias-adjusting field acts orthogonal to the field from the reference layer to change the angle between the magnetization of the free layer and the magnetization of the reference layer. For a scissoring-type read head, the bias-adjusting field acts parallel to the transverse bias field to change the angle between the magnetizations of the two free layers. This results in an improvement in the sensitivity of the read head to bring the soft error rate (SER) below an acceptable level.

Abstract: Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, an interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL and a second spin torque directed from the FGL to the SPL.

Abstract: The present invention generally relates to a read head in a magnetic recording head. The read head has side-by-side sensors that are formed of the same width by initially forming a single sensor and then removing selected portions of either the pinned or free magnetic layer of the sensor. Then, insulating material is filled into the area from where the selected portions have been removed. A hardmask may be necessary to properly define the side-by-side sensors to ensure that the selected portions of either the pinned or free magnetic layer are removed. The hardmask may be formed by blanket depositing hardmask material and then selectively removing the hardmask material such that the remaining hardmask material is equal to the width of the side-by-side sensors.

Abstract: Embodiments disclosed herein generally relate to magnetic recording systems having a spindle motor and, more particularly, to an optimized lubricant for bearings within the spindle motor. A lubricant used in a fluid dynamic bearing motor has an antioxidant additive and a charge control agent dissolved in a diester base oil. The charge control agent is chemically attached to the same diacid reactant used in the diester lubricant base oil, and is prepared through an esterification reaction. The charge control agent is then dissolved in the lubricant base oil. The charge control agent is soluble in the lubricant, and is resistant to free radical oxidation. The charge control agent effectively controls the charge of the lubricant by creating electron donor/acceptor sites in the lubricant, facilitating an independent electronic pathway through the lubricant.

Abstract: Embodiments of the invention provide an actuator head suspension assembly having an efficient voice coil. In one embodiment, a voice coil is formed in a circular or any other shape than the conventional sectorial shape to increase the efficiency of the voice coil and diminish oscillation and noise of an actuator head suspension assembly. The voice coil shape is selected such that the proportion of an out-of-plane force becomes smaller than that in the conventional sectorial voice coil and the proportion contributing as weight to the oscillation energy also becomes smaller.

Abstract: Systems, methods, and firmware for operating data storage devices and storage processors are provided herein. In one example, a data storage device is provided. The data storage device includes phase change media on which to write data, and a processing system configured to identify a write process to at least obfuscate an acoustic signature associated with writing the data on the phase change media and write the data to the phase change media in accordance with the write process.

Abstract: To provide enhanced operation of data storage devices and systems, various systems, methods, and software are provided herein. In a first example, a data storage system is configured to provide at least a portion of a first data storage device as a verification cache for a storage region of a second data storage device, write data for storage in the verification cache of the first data storage device and write the data for storage in the storage region of the second data storage device. The data storage system is configured to perform a verification process on the data written to the storage region after a verification trigger condition has been met. The data storage system is configured to transfer portions of the data that fail to pass the verification process from the verification cache to supersede the one or more parts of the data in the storage region.

Abstract: Cleaning a recording head slider in-drive during operation is accomplished by periodically performing a series of full stroke seek operations, whereby liquid contaminants that may have migrated to the head slider are flung from the slider and liquid from the disk surface may be adsorbed onto the slider for removal by way of flinging. Consequently, head-disk spacing may be stabilized and data write operations improved. Furthermore, the series of full stroke seek operations may be performed at predetermined intervals, and for a predetermined period of time. However, the series may be interrupted by a client request, and continued thereafter, so as not to affect the operational status of the recording system.

Abstract: A flash memory controller is configured to provide a first erase mode for erasing one or more groups of flash memory cells in a flash memory device using a plurality of erase pulses and a second erase mode for erasing the one or more groups of flash memory cells using a single erase pulse. The controller may receive a fast erase signal to erase the one or more groups of flash memory cells and, in response to the signal, switch operating parameters of the flash memory device from first parameters corresponding to the first erase mode to second parameters corresponding to the second erase mode, and instruct the flash memory device to perform an erase operation on the one or more groups of flash memory cells according to the second parameters. The controller may then verify that the erase operation was completed using the single erase pulse.

Abstract: An apparatus according to one embodiment includes a read sensor. The read sensor has an antiferromagnetic layer (AFM), a first antiparallel magnetic layer (AP1 ) positioned above the AFM layer in a first direction oriented along a media-facing surface and perpendicular to a track width direction, a non-magnetic layer positioned above the AP1 in the first direction, a second antiparallel magnetic layer (AP2) positioned above the non-magnetic layer in the first direction, a harrier layer positioned above the AP2 in the first direction, and a free layer positioned above the barrier layer in the first direction. A soft bias layer is positioned behind at least a portion of the free layer in an element height direction normal to the media-facing surface, the soft bias layer including a soft magnetic material configured to compensate for a magnetic coupling of the free layer with the AP2.

Abstract: Techniques for determining a relative spacing between a read head and a surface of a magnetic data storage device may use at least two magnetic spacing measurement patterns. A first magnetic spacing measurement pattern may be offset from a center of a data track by a first offset value and a second magnetic spacing measurement pattern may be offset by a second, different, offset value. A processor may determine a first harmonic tone and a second harmonic tone from each of the first and second magnetic spacing measurement patterns. The processor also may determine respective ratios between amplitudes of the first and second harmonic tones for each of the first and second magnetic spacing measurement patterns. The processor may determine which ratio is greater, and may utilize the greater ratio when determining relative spacing between the read head and the surface of the magnetic data storage device.