Abstract: The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; a head, configured to be positioned proximate to a disk surface among the one or more disks; a temperature sensor; and one or more processing devices. The one or more processing devices are configured to: detect, via the temperature sensor, a non-nominal heat dissipation of a portion of the head; and, in response to detecting the non-nominal heat dissipation of the portion of the head, mitigate the non-nominal heat dissipation of the portion of the head.

Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that has a media carbon dual-layer media carbon overcoat with both a carbon layer and a carbon-nitrogen (CN) layer. The carbon layer may be a plasma enhanced chemical vapor deposition (PECVD) carbon layer and the CN layer may be a sputtered CN layer. The dual-layer media carbon overcoat helps reduce a laser power requirement of an HAMR disk drive system and thus reduce the operating temperature of a near field transducer (NFT) of a HAMR disk drive. The dual-layer overcoat can also improve thermal and thermo-oxidative stability of the media and help retain a lubricant provided on the overcoat, therefore improving HAMR head-media interface reliability. The dual-layer media carbon overcoat can also reduce carbonaceous smear within a head-media gap.

Abstract: The present disclosure generally relates to using a data timestamp and/or a read counter to prevent data from being re-read and signal that the data has been accessed. The write assist element in the write head can be utilized to degrade the data or an allocated marker after the data has been read. The degradation functions as a read counter to indicate how many times the data has been read. Additionally and/or alternatively, a timestamp can be utilized. The timestamp is updated each time that the data has been accessed. In so doing, it is possible to determine whether data in a data storage device has been accessed.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write element, a read element, a laser, and a near field transducer. An operating thermal gradient of the magnetic media is periodically measured at an operating power setting for the laser that achieves a target magnetic write width. When a slope of the operating thermal gradient exceeds a threshold, a test thermal gradient and magnetic write width of the magnetic media is measured at multiple power settings for the laser in order to detect a contamination of the near field transducer.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write coil and a write pole. A test pattern is written to the magnetic media by applying a first current to the write coil. A second current is applied to the write coil while the head passes over the test pattern, wherein the second current has a polarity opposite the first current. After applying the second current to the write coil while the head passes over the test pattern, the test pattern is read from the magnetic media using the head to generate a first read signal, and a first noise power of the first read signal is measured. A degradation of the write pole is detected based on the first noise power measurement.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write coil and a write pole. A test pattern is written to the magnetic media by applying a first current to the write coil. A second current is applied to the write coil while the head passes over the test pattern, wherein the second current has a polarity opposite the first current. After applying the second current to the write coil while the head passes over the test pattern, the test pattern is read from the magnetic media using the head to generate a first read signal, and a first noise power of the first read signal is measured. A degradation of the write pole is detected based on the first noise power measurement.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a laser and a near field transducer (NFT). A thermal gradient produced in the magnetic media by the NFT is periodically measured, and a failure of the NFT is predicted based on a slope of the thermal gradient measurements.

Abstract: The present disclosure relates to pretreating a magnetic recording head to increase the lifetime of the magnetic media drive. A transparent smear is purposefully formed on the magnetic recording head to ensure the magnetic recording head does not overheat and lead to a short drive lifetime. The transparent smear is formed from material found in the magnetic media. The transparent smear is formed by pretreating the magnetic recording head with the transparent material from the magnetic media. The pretreating occurs without writing any data to the magnetic media. Once the transparent smear is in place, writing may occur. The magnetic recording head can be retreated at a later time should the transparent smear degrade. Furthermore, if an optically absorbing smear develop, it can be removed and a new transparent smear may be formed.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: The present disclosure relates to pretreating a magnetic recording head to increase the lifetime of the magnetic media drive. A transparent smear is purposefully formed on the magnetic recording head to ensure the magnetic recording head does not overheat and lead to a short drive lifetime. The transparent smear is formed from material found in the magnetic media. The transparent smear is formed by pretreating the magnetic recording head with the transparent material from the magnetic media. The pretreating occurs without writing any data to the magnetic media. Once the transparent smear is in place, writing may occur. The magnetic recording head can be retreated at a later time should the transparent smear degrade. Furthermore, if an optically absorbing smear develop, it can be removed and a new transparent smear may be formed.

Abstract: The present disclosure relates to a magnetic recording medium for a magnetic media drive. Absorbing smears can develop on magnetic recording heads during operation. The absorbing smears lead to shortened drive lifetime. Transparent smears, on the other hand, do not have as deleterious of an impact on drive lifetime as compared to absorbing smears. By doping the medium with a dopant that can lead to development of transparent smears, the formation of absorbing smears can be reduced or even eliminated, which leads to a longer drive lifetime. The dopant can be disposed in the capping layer of the medium or in the absorbing overcoat layer. The dopant will migrate through the medium to the top surface of the medium during operation. From the top surface of the medium, the dopant will deposit on the magnetic head and form a transparent smear.

Abstract: The present disclosure relates to pretreating a magnetic recording head to increase the lifetime of the magnetic media drive. A transparent smear is purposefully formed on the magnetic recording head to ensure the magnetic recording head does not overheat and lead to a short drive lifetime. The transparent smear is formed from material found in the magnetic media. The transparent smear is formed by pretreating the magnetic recording head with the transparent material from the magnetic media. The pretreating occurs without writing any data to the magnetic media. Once the transparent smear is in place, writing may occur. The magnetic recording head can be retreated at a later time should the transparent smear degrade. Furthermore, if an optically absorbing smear develop, it can be removed and a new transparent smear may be formed.

Abstract: A heat-assisted magnetic recording (HAMR) hard disk drive has a gas-bearing slider supporting a near-field transducer (NFT) and a NFT temperature sensor (NTS). An optional first IVC circuitry may provide a bias voltage to the slider body to assure substantially zero electrical potential between the slider body and the disk to minimize slider-disk contact and lubrication pick-up. A second IVC circuitry operates independently of the first IVC circuitry and provides a negative bias voltage to the NTS (and the connected NFT) relative to the disk to minimize the adverse effects of excessive heating on the NFT.

Abstract: A data storage device is disclosed comprising a head actuated over a disk surface, wherein the head comprises a plurality of elements including a write assist element. A bias signal applied to the write assist element is controlled such that the write assist element is substantially unprotruded, and while the write element is substantially unprotruded, an air bearing resonant frequency (ABRF) of the head and disk surface is measured. The bias signal applied to the write assist element is controlled such that the write assist element protrudes toward the disk surface, and while the write assist element protrudes toward the disk surface, the head is excited at the measured ABRF and the head touching down onto the disk surface is detected.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a write assist element. Data is written to the disk using the write assist element. A protrusion of the head toward the disk is measured periodically, and an abnormality with the write assist element is detected when a slope of the protrusion measurements indicates the protrusion is increasing.

Abstract: A hard disk drive has a gas-bearing slider supporting a write head with an electrically conductive structure, like a spin-torque oscillator (STO), in the write gap, and dual independent interface voltage control (IVC) circuitry coupled to elements on the slider. A first IVC circuitry provides a bias voltage to the slider body to assure substantially zero electrical potential between the slider body and the disk to minimize slider-disk contact and lubrication pick-up. A second IVC circuitry operates independently of the first IVC circuitry and provides a bias voltage to the electrically conductive structure region to assure a negative potential of the electrically conductive structure region relative to the disk to minimize degradation of the slider overcoat and thus oxidation of the electrically conductive structure.