Patent classifications
G11B2005/0018
Detecting damaged TMR sensors using bias currents and outliers
A computer-implemented method to detect a damaged tunneling magnetoresistance (TMR) sensor includes applying current at at least two different current values to the TMR sensor and measuring a resistance, R.sub.TMR, at each current value. The method also includes measuring a slope in resistance vs. bias current, RD.sub.SLP, using the measured resistances R.sub.TMR and the at least two different current values. The method includes calculating a ΔRD.sub.SLP value as a difference between the RD.sub.SLP value and an expected value, RD.sub.SLP-expected, for the TMR sensor. The method includes determining whether the ΔRD.sub.SLP value is within a predefined range. In response to determining that the ΔRD.sub.SLP value is outside the predefined range, the method includes outputting an indication that the TMR sensor fails. In response to determining that the ΔRD.sub.SLP value is within the predefined range, the method includes outputting an indication that the TMR sensor passes.
Energy assisted magnetic recording head having improved areal density capability
The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a main pole, an EAMR stack disposed on the main pole, and a trailing shield disposed on the EAMR stack. The EAMR stack comprises a seed layer disposed on the main pole, a spin torque layer disposed on the seed layer, and a spacer layer disposed on the spin torque layer. At least one surface of the spacer layer in contact with the spin torque layer has a smaller or reduced area than the spin torque layer. The at least one surface of the spacer layer in contact with the spin torque layer is recessed from a media facing surface and has a smaller cross-track width than the spin torque layer and a smaller width in the stripe height direction than the spin torque layer.
MAGNETIC DISK DEVICE
According to one embodiment, among a plurality of magnetic heads, the larger the magnetic pole width of the magnetic pole of the magnetic head in the width direction of a recording track formed in a recording layer or the larger an area width of the magnetic head capable of reading the magnetic characteristics of an area of the recording layer on which magnetic recording has been carried out by means of the magnetic head, the farther is the magnetic head arranged outwardly from the vicinity of the center in the parallel arrangement direction of the magnetic disks.
SOT Differential Reader And Method Of Making Same
The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device that comprises a first shield, a first spin hall effect layer, a first free layer, a gap layer, a second spin hall effect layer, a second free layer, and a second shield. The gap layer is disposed between the first spin hall effect layer and the second spin hall effect layer. Electrical lead connections are located about the first spin hall effect layer, the second spin hall effect layer, the gap layer, the first shield, and/or the second shield. The electrical lead connections facilitate the flow of current and/or voltage from a negative lead to a positive lead. The positioning of the electrical lead connections and the positioning of the SOT differential layers improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
Device lifetime improvement through constant temperature
The present disclosure generally relates to improved lifetime of a data storage device utilizing an energy assist element. Rather than applying the same current to each energy assist element of a device, each energy assist element has a write current specific to the energy assist element. The unique applied current results in the corresponding energy assist elements having substantially the same temperature during operation. Obtaining substantially the same temperature during operation provides predictable and repeatable device performance and increases the lifetime of the entire data storage device as all energy assist elements should have substantially the same lifetime.
BiSb Topological Insulator with Seed Layer or Interlayer to Prevent Sb Diffusion and Promote BiSb (012) Orientation
A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a seed layer over the substrate, and a bismuth antimony (BiSb) layer having (0120) orientation on the seed layer. The seed layer includes a silicide layer and a surface control layer. The silicide layer includes a material of NiSi, NiFeSi, NiFeTaSi, NiCuSi, CoSi, CoFeSi, CoFeTaSi, CoCuSi, or combinations thereof. The surface control layer includes a material of NiFe, NiFeTa, NiTa, NiW, NiFeW, NiCu, NiCuM, NiFeCu, CoTa, CoFeTa, NiCoTa, Co, CoM, CoNiM, CoNi, NiSi, CoSi, NiCoSi, Cu, CuAgM, CuM, or combinations thereof, in which M is Fe, Cu, Co, Ta, Ag, Ni, Mn, Cr, V, Ti, or Si.
Energy assisted magnetic recording head having improved areal density capability
The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a main pole, an EAMR stack disposed on the main pole, and a trailing shield disposed on the EAMR stack. The EAMR stack comprises a seed layer disposed on the main pole, a spin torque layer disposed on the seed layer, and a spacer layer disposed on the spin torque layer. At least one surface of the spacer layer in contact with the spin torque layer has a smaller or reduced area than the spin torque layer. The at least one surface of the spacer layer in contact with the spin torque layer is recessed from a media facing surface and has a smaller cross-track width than the spin torque layer and a smaller width in the stripe height direction than the spin torque layer.
Adaptive Bias Control for Magnetic Recording Head
A read head includes a permanent magnet (PM) layer formed up to 100 nm behind a free layer where PM layer magnetization may be initialized in a direction that adjusts free layer (FL) bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior measurement of asymmetry. The PM layer is CoPt or CoCrPt and has coercivity from 500 Oersted to 1000 Oersted. The PM layer may have a width equal to the FL, or in another embodiment, the PM layer adjoins a backside of the top shield and has a width equal to or greater than that of the FL.
Data storage device with history dependent write boost
A data storage device is disclosed comprising a head actuated over a magnetic media comprising a plurality of tracks. A first pattern of magnetic transitions is written to a first segment of a first track. Preparation is made to write a second pattern of magnetic transitions to a second segment of a second track adjacent the first segment of the first track. When the second pattern matches the first pattern, a write boost is configured to a first setting, and when the second pattern does not match the first pattern, the write boost is configured to a second setting. The second pattern of magnetic transitions is then written to the second segment of the second track using the configured write boost.
Read head stress reduction
Systems and methods are disclosed for dynamically adjusting parameters used during a read operation to reduce stress on a read head. In certain embodiments, an apparatus may comprise a read head configured to read data stored to a data storage medium, and a control circuit that controls a parameter of the read head influencing the read head's ability to accurately read data. The control circuit may be configured to extend the working lifespan of the read head by monitoring a read performance of the read head, and adjusting the parameter to reduce the read performance when the read performance is greater than a first threshold.