Abstract: Methods and apparatus for energy management in data storage devices are provided. One such data storage device (DSD) includes a non-volatile memory (NVM), a set of hardware processing engines, and a power sensor to detect a total power consumption of the set of hardware processing engines. A processor is configured to determine an energy-per-processing event value for each of the set of processing engines based on total power consumption measurements and processing event duration values, then control energy delivery to the processing engines based on the energy-per-processing event values in accordance with an energy budget. In some examples, the DSD employs a least-squares procedure to estimate power-per-processing event values so the values can be determined without needing to measure individual power consumption of the processing engines. The power-per-processing event values are converted to energy-per-processing event values based on corresponding processing event durations.

Abstract: A suspension assembly for a magnetic storage device. The suspension assembly includes a base plate, a load beam, and a flexure. A hinge of the load beam is configured to flex so that a distal end portion of the load beam moves relative to the base plate. The flexure includes a hinge portion and fixed portions adjacent the hinge portion. Each one of the fixed portions of the flexure includes a first layer and a second layer. The first layer is interposed between the second layer and the load beam. The hinge portion of the flexure includes the second layer but does not include the first layer. A thickness of the second layer of the hinge portion of the flexure is less than a thickness of the second layers of the fixed portions of the flexure.

Abstract: A node includes a memory configured to be used at least in part as a shared cache in a distributed cache. A network interface of the node is configured to communicate with one or more other nodes in a network. Each of the one or more other nodes is configured to provide a respective shared cache for the distributed cache. At least one processor of the node is configured to execute a kernel of an Operating System (OS) for allocating resources of the node. The kernel is used to collect cache access information for the shared cache for identifying malicious operations in the distributed cache.

Abstract: The present disclosure generally relates to a tape drive comprising one or more tape head modules and a method of forming thereof. A first element array and a second element array are disposed on a first chip of a rowbar, and a third element array and a fourth element array are disposed on a second chip of the rowbar. The second element array is centered on the first chip, and the fourth element array is centered on the second chip. The rowbar is split to separate the first and second chips, and the first and second chips are re-arranged before being bonded to a u-beam. The u-beam is split to form a first tape head module and a second tape head module. The first tape head module comprises the second chip and a congruent segment of the first chip. The second tape head module comprises the first chip.

Abstract: The present disclosure generally relates to magnetic recording devices comprising a read sensor. The sensor comprises a first buffer layer, a first ferromagnetic (FM) layer, the first FM layer comprising a single layer of Fe or FeSiAl, or a multilayer structure of Cr/Fe, NiAl/Fe, IrAl/Fe, FeSiAl/Fe, or Fe/FeSiAl, a first Co or CoFe interface layer, and a barrier layer. The sensor may further comprise a second Co or CoFe layer, and a second FM layer. The second FM layer may comprise a single layer of Fe or FeSiAl, or a multilayer structure of Fe/Cr, Fe/NiAl, Fe/IrAl, FeSiAl/Fe, or Fe/FeSiAl. The second FM layer may be amorphous. A synthetic anti-ferromagnetic (SAF) pinning and anti-ferromagnetic layer (AFM) may be disposed on the second FM layer. The sensor comprising one or more FM layers comprising Fe reduces the coercivity and magnetostriction and improves the stability of the read sensor.

Abstract: The present disclosure generally relates to a dual free layer (DFL) read head. The DFL read head comprises a first shield, a DFL sensor disposed on the first shield, soft bias (SB) side shields disposed adjacent to the DFL sensor on the first shield, a second shield disposed over the DFL sensor and SB side shields, and a rear soft bias (RSB) structure disposed adjacent to the DFL sensor, the RSB structure being recessed from a media facing surface. The RSB structure has a greater height than a width. The SB side shields comprise a first SB layer, a non-magnetic layer, and a second SB layer, the first and second SB layers being magnetically decoupled. The first SB layer is disposed in contact with a magnetic seed layer of the first shield. One of the first or second shields is synthetic anti-ferromagnetically pinned.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices comprise control circuitry which comprises an asynchronous demodulation module. The asynchronous demodulation module is configured to: receive demodulated split null burst signals based on the selected head reading a first set of bursts and a second set of bursts in a split burst servo pattern of the corresponding disk surface; and output, based on the demodulated split null burst signals, a radial position signal, indicative of a radial position of the selected head.

Abstract: A method of adjusting a humidity within an interior of an enclosure of a data storage device comprises detecting a trigger condition, and in response to detecting the trigger condition, heating a water-releasing substance situated within the interior of the enclosure of the data storage device to release water, thereby increasing the humidity within the interior of the enclosure of the data storage device. A data storage device comprises a water-releasing substance; a heater configured to heat the water-releasing substance; and a controller configured to control the heater to cause the water-releasing substance to release water.

Abstract: Systems for detecting magnetic particles comprising a detection device with a fluid region, a magnetochemical sensor configured to detect magnetic particles in the fluid region, the magnetochemical sensor including a sensing region, and a conductive structure configured to conduct current to generate a magnetic field gradient at the sensing region that directs magnetic particles in the fluid region toward the sensing region of the magnetochemical sensor. A direction of current flow through the conductive structure is oriented relative to a sensing axis of the magnetochemical sensor to control alignment of the magnetic field gradient with the sensing region. The direction may be perpendicular or parallel to an in-plane sensing axis of the magnetochemical sensor.

Abstract: Embodiments of the present disclosure generally relate to a vertical cavity surface emitting laser (VCSEL), a head gimbal assembly for mounting a VCSEL, devices incorporating such articles, and to a process for forming a VCSEL. In an embodiment, a process for forming a VCSEL device is provided. The process includes forming a trench in a substrate, forming two laser diode electrodes in the trench, and after forming the two laser diode electrodes, cutting the substrate along the trench to form a VCSEL, the VCSEL comprising a chip for mounting on a slider, the chip having six surfaces, wherein a first surface of the chip is for facing the slider, a second surface of the chip is opposite the first surface, the two laser diode electrodes being positioned in any combination on one or more of a third surface, a fourth surface, a fifth surface, or a sixth surface.

Abstract: A VCSEL array has VCSEL sub-arrays having VCSELs on a substrate. The sub-arrays are electrically contacted by a first electrical contact arrangement common to the VCSELs within a respective sub-array and a second electrical contact arrangement. The second electrical contact arrangement has second electrical contacts contacting a respective VCSEL within the respective sub-array, individually. The second electrical contacts each has a second metal-semiconductor interface to a second semiconductor layer of an associated VCSEL. The second electrical contacts pump the VCSEL along a current path to the first electrical contact arrangement. Current paths between the first electrical contact arrangement and the second electrical contacts via the VCSELs have a symmetry selected out of the group of rotation symmetry, mirror symmetry, and translation symmetry. The first electrical contact arrangement and the second electrical contact arrangement are arranged on the same side of the substrate.

Abstract: An aromatic or aromatic-like group(s) containing lubricant configured to be adsorbed by a magnetic recording media is formed from where Ar is an aromatic group, polyaromatic hydrocarbon (PAH), annulene, cycloalkane or heterocycle, m=1-10, R1 and R2 are moieties containing first and second polar groups, respectively, Rf is a perfluorinated polyether, o=1-10, p=0-10, and q=1-10. The first or second polar group may independently be hydroxyl, phosphonic acid, silanol or carboxylic acid. In an embodiment, the lubricant has the formula: where Ar is a system formed from a PAH, annulene, cycloalkane or heterocycle, X, Y and Z can independently be hydroxyl, a phosphonic acid moiety, a silanol or a carboxylic acid moiety, and where Rf may be CF2O(CF2CF2)nCF2— where n is 1 to 100. Synthesizing the lubricant may entail reacting parabromophenol with (Ar)m(R1oRfR2p)q.

Abstract: The present disclosure is generally directed towards a data storage device comprising a crystalline salt configured to release oxygen. The crystalline salt comprises a cation and a counteranion. The counteranion may be selected from the group consisting of: ClO4—, PF6—, BF4—, CF3SO3—, and NO3—. In one embodiment, the cation is ([(2-pyridylmethyl)aminomethyl)-4-tert-butylphenolato)M2(O2)(R1)m]2m+)n, where M is selected from the group consisting of: Co, Ni, Mn, Fe, and Cu, and R1 is caboxylated and selected from the electron donating or drawing group consisting of: F, Cl, Br, I, carbonyl, carboxyl, hydroxyl, alkyl, aryl, amine, amide, and nitro. In the cation, n is a numeral between 0 and 4, and m is a numeral between 1 and 100, where m represents the number of repeating units of the cation. The crystalline salt is configured to release oxygen above about 30° C. to maintain a level of about 8% to about 12% of oxygen.

Abstract: The present disclosure generally relates to a magnetic recording head comprising a read head. The read head comprises a first sensor disposed at a media facing surface (MFS) comprising at least one free layer, a second sensor disposed at the MFS comprising at least one free layer, a first spin generator spaced from the first sensor and recessed from the MFS, and a second spin generator spaced from the second sensor and recessed from the MFS. The first and second spin generators each individually comprises at least one spin orbit torque (SOT) layer. The SOT layer may comprise BiSb. The first and second sensors are configured to detect a read signal using a first voltage lead and a second voltage lead. The first and second spin generators are configured to inject spin current through non-magnetic layers to the first and second sensors using a plurality of current leads.

Abstract: A double mask process may be used to define layers of a near field transducer (NFT) to enable independent control over each layer. Controlling critical features of the NFT, including the apex width, taper angles, and flare angles is important for achieving desired areal density capabilities (ADC) of heat-assisted magnetic recording (HAMR) devices. By using a first mask to define a first layer of the NFT then a second mask to define a second layer of the NFT, limitations of the single mask NFT definition process may be overcome. For example, the limitation of using the same flare shape for both the first and the second NFT layers. Further, since the apex width of the NFT is defined by a separate mask, further scaling down of the apex width may also be achieved in a double mask NFT definition process.

Abstract: The present disclosure generally relates to a tape head module assembly and a tape drive including the tape head module assembly. The tape head module assembly comprises a first tape head module disposed on a first actuator and a second tape head module disposed on a second actuator. The first actuator is configured to move the first tape head module in a first direction and a second direction opposite the first direction to tilt the first tape head module, and the second actuator is configured to move the second tape head module in the first direction and the second direction to tilt the second tape head module. The first tape head module is operable to write data to a tape using perpendicular magnetic recording, and the second tape head module is operable to read-verify the newly written data.

Abstract: Disclosed herein are sliders with at least one notch in the trailing pad, methods of making them, and data storage devices comprising them. In some embodiments, a slider comprises a leading-edge surface, a trailing-edge surface, and an air-bearing surface (ABS) that includes a trailing pad situated closer to the trailing-edge surface than to the leading-edge surface, wherein the trailing pad comprises a main portion, a mini-pad situated between the main portion and the trailing-edge surface, and a neck portion connecting the mini-pad to the main portion, wherein a minimum width of the neck portion in a cross-track direction is less than a minimum width of the mini-pad in the cross-track direction.

Abstract: Systems, methods, and a bridge device for a data storage device array that enables data transfer between data storage devices without transferring data to the host system are described. The bridge device receives a data transfer command from the host system, such as a fused read and write command, and converts it to separate read and write commands for the source and destination storage devices. The bridge device may operate in a non-volatile memory express over fabric (NVMe-oF) environment and manage the command queues, connection verifications, and command conversions to enable data transfer among storage devices connected to a shared peripheral component interface express (PCIe) root complex without using host network bandwidth or memory.

Abstract: A data storage device comprises a disk; a head configured to read data from and write data to the disk; and a current balancer configured to receive a first voltage supply having a load limit and to receive a second voltage supply. The current balancer is further configured, to reduce power consumption, to sample a first current drawn from the first voltage supply, to maintain the first current at a target level that approximately equals the load limit, and to draw a second current from the second voltage supply to satisfy a part of a total load on the first voltage supply that exceeds the load limit.

Abstract: The present disclosure generally relates to spin-orbit torque (SOT) device comprising a bismuth antimony (BiSb) layer. The SOT device comprises a seed layer and a BiSb layer having a (012) orientation. The seed layer comprises at least one of an amorphous/nanocrystalline material with a nearest neighbor x-ray diffraction peak with a d-spacing in the range of about 2.02 ? to about 2.20 ?; a polycrystalline material having a (111) orientation and an a-axis of about 3.53 ? to about 3.81 ?; and a polycrystalline material having a cubic (100) or tetragonal (001) orientation and an a-axis of about 4.1 ? to about 4.7 ?. When the seed layer comprises an amorphous material or a polycrystalline material having a (111), the BiSb layer is doped, and the seed layer has a lower a/c ratio than when the seed layer comprises polycrystalline material having a cubic (100) or tetragonal (001) orientation.