Abstract: A magnetic head includes a main magnetic pole, a write shield separated from the main magnetic pole by a write gap, a first side shield that is separated from the main magnetic pole by a first side gap, a second side shield that is separated from the main magnetic pole by a second side gap, a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield, and a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein the first magnetic relative permeability is smaller than the second magnetic relative permeability.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head for writing data to the disk and reading data from the disk, and a controller configured to detect a positioning error of the head as the head is writing the data in a first track of the disk, and change a first threshold value for interrupting the writing based on one or more evaluation values corresponding to a possibility of correcting error data in the first track of the disk. The controller interrupts the writing when detecting the positioning error of the head writing the first track that exceeds the first threshold value.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes a magnetic flux control layer provided between a main magnetic pole and an auxiliary magnetic pole, and a protective layer provided on an ABS of the auxiliary magnetic pole. The magnetic flux control layer includes an adjustment layer formed of a magnetic material includes one of Fe, Co or Ni and provided between a first conductive layer and a second conductive layer, and generates a spin torque and inverts a direction of magnetization in the adjustment layer, when current is supplied. A voltage Vb applied to the magnetic flux control layer is lower than a voltage Vba represented by an expression (1).

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head for writing data to the disk and reading data from the disk, and a controller configured to detect a positioning error of the head as the head is writing the data in a first track of the disk, and change a first threshold value for interrupting the writing based on one or more evaluation values corresponding to a possibility of correcting error data in the first track of the disk. The controller interrupts the writing when detecting the positioning error of the head writing the first track that exceeds the first threshold value.

Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

Abstract: According to one embodiment, a magnetic disk device conforming to perpendicular magnetic recording includes a magnetic disk, a recording head, and a controller. The head includes a main magnetic pole, a return magnetic pole, a recording coil, and a conductive member in which end surfaces are connected to opposed surfaces of a write gap which is opposed to a distal portion of the main magnetic pole and a distal portion of the return magnetic pole, and a resistance value varies. The controller applies a current to the recording coil to excite the magnetic flux in the recording operation, and applies a current at a constant voltage to the magnetic circuit via the comductive member.

Abstract: A magnetic recording apparatus includes a disk-shaped recording medium with a magnetic recording layer, and a recording head that magnetically writes data onto the magnetic recording layer and includes a main magnetic pole, a write shield facing the main magnetic pole and positioned with a writing gap disposed between the main magnetic pole and the write shield, and a magnetic flux control layer disposed inside the write gap between the main magnetic pole and the writing shield. The magnetic flux control layer includes a first layer including a first metal and contacting one of the main magnetic pole and the writing shield, a second control layer, and a third layer including a second metal and contacting the other one of the main magnetic pole and the writing shield. The second control layer includes a magnetic metal and contacts the first layer and the third layer.

Abstract: A magnetic recording apparatus includes a disk-shaped recording medium with a magnetic recording layer, and a recording head that magnetically writes data onto the magnetic recording layer and includes a main magnetic pole, a write shield facing the main magnetic pole and positioned with a writing gap disposed between the main magnetic pole and the write shield, and a magnetic flux control layer disposed inside the write gap between the main magnetic pole and the writing shield. The magnetic flux control layer includes a first layer including a first metal and contacting one of the main magnetic pole and the writing shield, a second control layer, and a third layer including a second metal and contacting the other one of the main magnetic pole and the writing shield. The second control layer includes a magnetic metal and contacts the first layer and the third layer.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole having a first surface, a first shield separated from the magnetic pole along the first surface, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a magnetic layer, and first and second conductive layers. The magnetic layer includes at least one selected from the group consisting of Fe, Co, and Ni. The first conductive layer contacts the magnetic pole and the magnetic layer, and is provided between the magnetic pole and the magnetic layer. The second conductive layer contacts the magnetic layer and the first shield, is provided between the magnetic layer and the first shield. The first shield has a first shield surface contacting the second conductive layer. A ratio of a length of the magnetic layer to a length of the first shield surface is 0.1 or more.

Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole having a first surface, a first shield separated from the magnetic pole along the first surface, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a magnetic layer, and first and second conductive layers. The magnetic layer includes at least one selected from the group consisting of Fe, Co, and Ni. The first conductive layer contacts the magnetic pole and the magnetic layer, and is provided between the magnetic pole and the magnetic layer. The second conductive layer contacts the magnetic layer and the first shield, is provided between the magnetic layer and the first shield. The first shield has a first shield surface contacting the second conductive layer. A ratio of a length of the magnetic layer to a length of the first shield surface is 0.1 or more.

Abstract: A magnetic recording apparatus includes a magnetic recording medium; a magnetic recording head including a first magnetic pole part, a second magnetic pole part, and a magnetic flux control part provided between the first magnetic pole part and the second magnetic pole part, wherein the magnetic flux control part includes a first layer provided between the first magnetic pole part and the second magnetic pole part, a second layer provided between the first magnetic pole part and the first layer, and a third layer provided between the second magnetic pole part and the first layer; an electrode for applying a current to the magnetic flux control part; and an electric circuit for energizing the current to the electrode, wherein an oscillation frequency of magnetization of the magnetic layer is greater than a ferromagnetic resonance frequency of the magnetic recording medium.

Abstract: A magnetic head includes a main magnetic pole, a write shield separated from the main magnetic pole by a write gap, a first side shield that is separated from the main magnetic pole by a first side gap, a second side shield that is separated from the main magnetic pole by a second side gap, a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield, and a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein the first magnetic relative permeability is smaller than the second magnetic relative permeability.

Abstract: According to one embodiment, a magnetic disk device conforming to perpendicular magnetic recording includes a magnetic disk, a recording head, and a controller. The head includes a main magnetic pole, a return magnetic pole, a recording coil, and a conductive member in which end surfaces are connected to opposed surfaces of a write gap which is opposed to a distal portion of the main magnetic pole and a distal portion of the return magnetic pole, and a resistance value varies. The controller applies a current to the recording coil to excite the magnetic flux in the recording operation, and applies a current at a constant voltage to the magnetic circuit via the comductive member.

Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.

Abstract: A magnetic recording apparatus includes a magnetic recording medium; a magnetic recording head including a first magnetic pole part, a second magnetic pole part, and a magnetic flux control part provided between the first magnetic pole part and the second magnetic pole part, wherein the magnetic flux control part includes a first layer provided between the first magnetic pole part and the second magnetic pole part, a second layer provided between the first magnetic pole part and the first layer, and a third layer provided between the second magnetic pole part and the first layer; an electrode for applying a current to the magnetic flux control part; and an electric circuit for energizing the current to the electrode, wherein an oscillation frequency of magnetization of the magnetic layer is greater than a ferromagnetic resonance frequency of the magnetic recording medium.

Abstract: According to one embodiment, a magnetic recording medium including a substrate and a magnetic recording layer formed on the substrate and including a plurality of projections is obtained. The array of the plurality of projections includes a plurality of domains in which the projections are regularly arranged, and a boundary region between the domains, in which the projections are irregularly arranged. The boundary region is formed along a perpendicular bisector of a line connecting the barycenters of adjacent projections.

Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.