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 recording device includes a magnetic head, a first electrical circuit, and a second electrical circuit. The magnetic head includes a magnetic pole, a first shield, a conductive member electrically connecting the magnetic pole and the first shield and being provided between the magnetic pole and the first shield, and a coil. The first electrical circuit is configured to supply a first current to the magnetic pole, the conductive member, and the first shield. The second electrical circuit is configured to supply a recording current to the coil. A recording magnetic field is generated from the magnetic pole. The recording magnetic field corresponds to the recording current. A rise time of the recording current is not less than 65% of a shortest bit length.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole, a first shield, a magnetic layer, a first conductive layer, and a second conductive layer. The magnetic layer is provided between the magnetic pole and the first shield. The first conductive layer includes at least one of Cu, Ag, Au, Al and Cr, and is provided between the magnetic pole and the first shield. A direction from the first conductive layer toward the magnetic layer crosses a first direction from the magnetic pole toward the first shield. A second conductive layer includes at least one of Ta, Pt, W, Ru, Mo, Ir, Rh, and Pd and is provided at one of a first position or a second position. The first position is between the first conductive layer and the first shield. The second position is between the magnetic pole and the first conductive layer.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole, first and second shield regions, and a first stacked body. A direction from the magnetic pole toward the first shield region is aligned with a first direction. A direction from the magnetic pole toward the second shield region crosses the first direction. The first stacked body is provided between the magnetic pole and the second shield region. The first stacked body includes a first magnetic layer including at least one selected from the group consisting of Fe, Co, and Ni, a first conductive layer provided between the magnetic pole and the first magnetic layer, and a second conductive layer provided between the first magnetic layer and the second shield region. The first direction is aligned with a direction of relative movement between the magnetic pole and a magnetic recording medium. The magnetic pole opposes the magnetic recording medium.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole, a first shield, a second shield, a first stacked body and a second stacked body. At least a portion of the magnetic pole is provided between the first and second shields. The first stacked body is provided between the magnetic pole and the first shield. The second stacked body is provided between the magnetic pole and the second shield. The first stacked body includes a first magnetic layer including, a first conductive layer provided between the magnetic pole and the first magnetic layer, and a second conductive layer provided between the first magnetic layer and the first shield. The second stacked body includes a second magnetic layer including, a third conductive layer provided between the magnetic pole and the second magnetic layer, and a fourth conductive layer provided between the second magnetic layer and the second shield.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole, a first shield, and a stacked body. The stacked body is provided between the magnetic pole and the first shield. The stacked body includes a magnetic layer including at least one selected from the group consisting of Fe, Co, and Ni, a first conductive layer provided between the magnetic pole and the magnetic layer, the first conductive layer being nonmagnetic, and a second conductive layer provided between the magnetic layer and the first shield, the second conductive layer being nonmagnetic. The first conductive layer includes Ir. A thickness of the first conductive layer along a first direction is not less than 0.3 nm and not more than 0.8 nm. The first direction is from the first conductive layer toward the second conductive layer.

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, a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a first layer, the first layer being nonmagnetic, a second layer provided between the first layer and the first shield, the second layer being nonmagnetic, and a third layer contacting the first layer and the second layer, being provided between the first layer and the second layer, and being electrically connected to the first layer and the second layer. The third layer includes a first magnetic region, and a second magnetic region contacting the first magnetic region and being provided between the first magnetic region and the second layer. A second saturation magnetization of the second magnetic region is higher than a first saturation magnetization of the first magnetic region.

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 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, a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a first layer, the first layer being nonmagnetic, a second layer provided between the first layer and the first shield, the second layer being nonmagnetic, and a third layer contacting the first layer and the second layer, being provided between the first layer and the second layer, and being electrically connected to the first layer and the second layer. The third layer includes a first magnetic region, and a second magnetic region contacting the first magnetic region and being provided between the first magnetic region and the second layer. A second saturation magnetization of the second magnetic region is higher than a first saturation magnetization of the first magnetic region.

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: According to one embodiment, a magnetic head includes a magnetic pole, and a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a first layer, a second layer and a third layer. The first layer includes at least one first element selected from the group consisting of Fe, Co, and Ni. The second layer is provided between the magnetic pole and the first layer, and includes at least one second element selected from the group consisting of Cr, V, Mn, Ti, and Sc. The third layer is provided between the first layer and the first shield, and includes at least one third element selected from the group consisting of Cr, V, Mn, Ti, and Sc.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes an output driver, a magnetic head, and a magnetic recording medium. The output driver outputs a recording signal corresponding to input information. The magnetic head includes a coil. A recording current includes the recording signal flows in the coil. Information corresponding to the input information is recorded in the magnetic recording medium. The input information includes first, second, and third information combinations. The first information combination includes first to fourth information. The second information combination includes fifth to eighth information. The third information combination includes ninth to twelfth information. The recording signal changes to an eleventh recording current to correspond to the eleventh information. The recording signal changes to a third recording current to correspond to the third information.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes an output driver, a magnetic head, and a magnetic recording medium. The output driver outputs a recording signal corresponding to input information. The magnetic head includes a coil. A recording current includes the recording signal flows in the coil. Information corresponding to the input information is recorded in the magnetic recording medium. The input information includes first, second, and third information combinations. The first information combination includes first to fourth information. The second information combination includes fifth to eighth information. The third information combination includes ninth to twelfth information. The recording signal changes to an eleventh recording current to correspond to the eleventh information. The recording signal changes to a third recording current to correspond to the third information.