Disclosed here is a magnet for use in a motor. The magnet comprises a magnet body. The magnet body comprises a plurality of coated magnetic granules. Each coated magnetic granule of the plurality of coated magnetic granules comprises a magnetic granule and a metallic layer coating the magnetic granule.

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, including a first data track and a second data track. In connection with writing to at least part of the first data track, a quality metric is measured for at least part of the first data track. In connection with writing to at least part of the second data track, a refresh metric is updated based on the write to at least part of second data track and the quality metric measured for the first data track, and at least the first data track is refreshed based on the refresh metric.

According to one embodiment, a magnetic disk device includes a disk, a head including a write head that writes data to the disk, and a first read head and a second read head that read data from the disk, and a controller that, in reading a first track of a first region of the disk, positions a middle portion of the first read head and the second read head at a first track center of the first track, and in reading a second track of a second region of the disk different from the first region, positions any one of the first read head and the second read head at a second track center of the second track.

A data storage device is disclosed wherein an elevator actuator is controlled to move a head along an axial dimension toward a first disk surface of a first disk while processing a proximity signal generated by a proximity sensor. A first actuator position is detected when the actuator arm is proximate the first disk surface of the first disk based on the proximity signal.

A magnetic disk device includes a disk, a head comprising a main magnetic pole and a write shield, and configured to generate a magnetic field from the main magnetic pole to the write shield to write data onto the disk, an assist element configured to assist the writing by generating a magnetic field or heating a surface of the disk, and a controller configured to control the head to write the data according to either a first recording method using the assist element or a second recording method not using the assist element depending on a condition of the assist element.

A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk surface, and a second actuator configure to actuate a second head over a second disk surface. A first seek of the first head over the first disk surface is initiated during a first seek time based on a first seek profile. A second seek of the second head over the second disk surface is initiated during a second seek time based on a second seek profile. When the second seek time at least partially overlaps the first seek time and at least the second seek profile is a de-rated seek profile, the second seek profile is adjusted to avoid an overcurrent condition.

According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, an actuator including a voice coil motor that moves the head over the disk, and a controller that increases a second current value applied to the voice coil motor during deceleration of the head in a seek according to a first current value that is maximum value capable of being applied to the voice coil motor during acceleration of the head in the seek on the disk.

A magnetic disk device includes a disk, a head comprising a main magnetic pole and a write shield, and configured to generate a magnetic field from the main magnetic pole to the write shield to write data onto the disk, an assist element configured to assist the writing by generating a magnetic field or heating a surface of the disk, and a controller configured to control the head to write the data according to either a first recording method using the assist element or a second recording method not using the assist element depending on a condition of the assist element.

Disclosed here is a magnet comprising a magnet body. The magnet body comprises a plurality of coated magnetic granules. Each coated magnetic granule of the plurality of coated magnetic granules comprises a magnetic granule and a metallic layer coating the magnetic granule

According to one embodiment, a magnetic disk device includes a disk, a head including a write head that writes data to the disk, and a first read head and a second read head. that read data from the disk, and a controller that, in reading a first track of a first region of the disk, positions a middle portion of the first read head and. the second read head at a first track center of the first track, and in reading a second track of a second region. of the disk different from the first region, positions any one of the first read head and the second read. bead at a second track center of the second track.