A change in servo active gain control values is determined from a beginning of a writing of a test region of a recording medium to an end of the writing of the test region. The servo active gain control values are read from servo marks by a read transducer of a read/write head during the writing. After writing of the test region, the test region is read by the read transducer to determine a change in recorded amplitude from the beginning of the writing to the end of the writing. A gamma value of the read/write head is determined based on the change in servo active gain control values and the change in recorded amplitude.

A sensor supported by a head transducer has a temperature coefficient of resistance (TCR) and a sensor resistance. The sensor operates at a temperature above ambient and is responsive to changes in sensor-medium spacing. Conductive contacts connected to the sensor have a contact resistance and a cross-sectional area adjacent to the sensor larger than that of the sensor, such that the contact resistance is small relative to the sensor resistance and negligibly contributes to a signal generated by the sensor. A multiplicity of head transducers each support a TCR sensor and a power source can supply bias power to each sensor of each head to maintain each sensor at a fixed temperature above an ambient temperature in the presence of heat transfer changes impacting the sensors. A TCR sensor of a head transducer can include a track-oriented TCR sensor wire for sensing one or both of asperities of the medium.

This thin film magnetic head includes: a magnetic pole including an end surface exposed on an air bearing surface; and a heating element including a first branch and a second branch and configured to heat a vicinity of the magnetic pole. The first branch and the second branch each expand along a stacking surface and are coupled in parallel to each other. The stacking surface intersects the air bearing surface.

A data storage device may have increased signal-to-noise ratio contact detection by employing a transducing head associated with a data storage medium each connected to a controller. The transducing head can have an alternating current heater excited to a first frequency for a first revolution of the data storage medium and to a different second frequency for a second revolution of the data storage medium. The second frequency may produce lateral transducing head motion as a result of physical contact of the transducing head with the data storage medium. The controller can issue a contact status in response to comparing a first plurality of position error signals logged during the first frequency to a second plurality of position error signals logged during the second frequency.

Implementations described and claimed herein includes a storage device comprising a transducer heat including at least one pair of read/write elements and a heat shaped to thermally protrude regions of the transducer head including the read/write elements. According to one implementation, the heat element includes at least one conductive portion of locally decreased resistance proximal to and between the pair of read/write elements to direct the thermally protruded close point away from a midpoint between the read/write elements.

Aspects of the present disclosure provide various magnetic recording slider structures and fabrication methods that can reduce head overcoat (HOC) thickness without significantly reducing the lifetime and reliability of a slider by using a protective cap placed on preselected locations on the outermost surface or HOC of the slider. A slider includes a writer comprising an energy-assisted recording element. The writer is configured to store information on a magnetic medium using the energy-assisted recording element. The slider includes a head overcoat (HOC) layer providing an outermost media facing surface. The slider further includes a protective cap positioned on the HOC layer to at least partially cover the energy-assisted recording element, the protective cap including a preselected shape configured to protect the energy-assisted recording element.

A Perpendicular Magnetic Recording (PMR) head is configured for use in Thermally Assisted Magnetic Recording (TAMR). Two or three contiguous write shields, of various widths and thicknesses, formed on a leading edge side of the write gap (WG), main pole (MP) and near-field transducer (NFT), protect the head during write touchdowns (TD) and signal the approach of such a touchdown. Moreover during a write touchdown the contact with the head is restricted to the large write shields, producing a large touchdown area (TDA) and insuring the lifetime of the head.

A thermally assisted magnetic head includes a slider, the slider includes a slider substrate and a magnetic head part. The magnetic head part includes a recording head, a reading head, a near field transducer and a medium-opposing surface. The medium-opposing surface includes a recording area and a reading area. The magnetic head part includes a record/read separately protective structure which a stabilized protective film is formed on the recording area and a reading head protective film is formed on the reading area. The stabilized protective film includes a three-layers structure which a seed layer and a double protective layer are laminated. The double protective layer includes a YSZ protective layer and a hard protective layer. The reading head protective film includes a thickness which is thinner than the stabilized protective film.

An apparatus comprises a slider comprising an air bearing surface (ABS). The slider comprises a reader, a writer, and a reader heater. The reader heater is configured to cause a protrusion of the ABS proximate the reader, and the reader heater comprises a first planar loop and a second planar loop, wherein the first and second loops are in the same plane.

A data storage device (DSD) includes a base-deck, a disc above the base-deck, and a shaft extending perpendicular from the base-deck. The DSD also includes a head stack assembly (HSA) including a head gimbal assembly having a load beam and a head at a first end of the HSA. The head interacts with a surface of the disc. The HSA also includes a second end movably mounted on the shaft. The DSD additionally includes an elevator that linearly moves the HSA along the shaft to adjust a distance between the load beam and the surface of the disc in response to receiving a feedback signal associated with the interaction of the head with the surface of the disc. The feedback signal is one of a plurality of feedback signals employed by the elevator to adjust the distance between the load beam and the surface of the disc.