According to one embodiment, a disk device includes a recording medium, a magnetic head, a ramp, and an actuator. The recording medium has a recording surface and is rotatable around a first rotation axis. The actuator includes a first portion extending so as to be separated from a second rotation axis and separated from the recording surface as the distance from the second rotation axis increases, holds the magnetic head, and is rotatable around the second rotation axis. A first support is provided on the ramp, extends around the second rotation axis, and can support the first portion so that the magnetic head is separated from the recording surface. A second support is provided on the ramp, is located between the first rotation axis and the first support, is separated from the second rotation axis farther than the first support, and can support the first portion.

According to one embodiment, a disk device includes a recording medium, a magnetic head, a ramp, and an actuator. The recording medium has a recording surface and is rotatable around a first rotation axis. The actuator includes a first portion extending so as to be separated from a second rotation axis and separated from the recording surface as the distance from the second rotation axis increases, holds the magnetic head, and is rotatable around the second rotation axis. A first support is provided on the ramp, extends around the second rotation axis, and can support the first portion so that the magnetic head is separated from the recording surface. A second support is provided on the ramp, is located between the first rotation axis and the first support, is separated from the second rotation axis farther than the first support, and can support the first portion.

A magnetic recording medium includes a substrate, a soft magnetic underlayer on the substrate, and a dual seed layer. The dual seed layer includes a first seed layer comprising NiFe at a first concentration, and a second seed layer comprising NiFe at a second concentration different from the first concentration and a segregant. The first seed layer may be on a soft magnetic underlayer and the second seed layer is on the first seed layer. The magnetic recording medium may further include one or more magnetic recording layers on the dual seed layer. The magnetic recording medium with the composition-graded dual seed layer may provide small grain size and good crystallographic texture for layers on the dual seed layer, including the magnetic recording layers.

A magnetic recording medium includes a substrate, a soft magnetic underlayer on the substrate, and a dual seed layer. The dual seed layer includes a first seed layer comprising NiFe at a first concentration, and a second seed layer comprising NiFe at a second concentration different from the first concentration and a segregant. The first seed layer may be on a soft magnetic underlayer and the second seed layer is on the first seed layer. The magnetic recording medium may further include one or more magnetic recording layers on the dual seed layer. The magnetic recording medium with the composition-graded dual seed layer may provide small grain size and good crystallographic texture for layers on the dual seed layer, including the magnetic recording layers.

Systems and methods are disclosed for synchronous writing of a grain patterned medium. The systems and methods can be implemented within a data storage device having a grain patterned medium. Further, a calibration process to determine a count of bits between servo wedges can be implemented in manufacturing, within the data storage device, or both. In some examples, the data storage device, during operation, can utilize the count of bits to perform synchronous writing, determine write errors, or both. Further, the servo wedge of the grain patterned medium may be patterned with a same or similar grain pattern as the data area that follows the servo wedge. Such a data storage device can implement a single clock for reading a servo wedge and writing a data area.

Systems and methods are disclosed for synchronous writing of a grain patterned medium. The systems and methods can be implemented within a data storage device having a grain patterned medium. Further, a calibration process to determine a count of bits between servo wedges can be implemented in manufacturing, within the data storage device, or both. In some examples, the data storage device, during operation, can utilize the count of bits to perform synchronous writing, determine write errors, or both. Further, the servo wedge of the grain patterned medium may be patterned with a same or similar grain pattern as the data area that follows the servo wedge. Such a data storage device can implement a single clock for reading a servo wedge and writing a data area.

According to one embodiment, a magnetic disk device comprises a magnetic disk, a magnetic head, a monitoring unit, and a control unit. When carrying out write of data to a first track, if an absolute difference between a light output monitored by the monitoring unit at the time of write and a light output monitored last time by the monitoring unit exceeds a predetermined value, the control unit controls a position of a write head and writes data again to the first track or a second track one track before the first track.

According to one embodiment, a magnetic disk device comprises a magnetic disk, a magnetic head, a monitoring unit, and a control unit. When carrying out write of data to a first track, if an absolute difference between a light output monitored by the monitoring unit at the time of write and a light output monitored last time by the monitoring unit exceeds a predetermined value, the control unit controls a position of a write head and writes data again to the first track or a second track one track before the first track.

According to one embodiment, a magnetic reproducing and processing device includes an acquirer and a processor. The acquirer is configured to acquire a first electric signal obtained by reproducing information recorded in a first recording area of a magnetic recording medium by a first reproducing element and a second electric signal obtained by reproducing the information recorded in the first recording area by a second reproducing element. A first sensitivity of the first reproducing element to a magnetic signal recorded on the magnetic recording medium is different from a second sensitivity of the second reproducing element to the magnetic signal. The processor is configured to output a reproduced signal corresponding to the information recorded in the first recording area based on the first electric signal and the second electric signal acquired by the acquirer.

According to one embodiment, a magnetic reproducing and processing device includes an acquirer and a processor. The acquirer is configured to acquire a first electric signal obtained by reproducing information recorded in a first recording area of a magnetic recording medium by a first reproducing element and a second electric signal obtained by reproducing the information recorded in the first recording area by a second reproducing element. A first sensitivity of the first reproducing element to a magnetic signal recorded on the magnetic recording medium is different from a second sensitivity of the second reproducing element to the magnetic signal. The processor is configured to output a reproduced signal corresponding to the information recorded in the first recording area based on the first electric signal and the second electric signal acquired by the acquirer.