Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a fourth magnetic layer provided between the second magnetic pole and the third magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second and first magnetic layers, a third non-magnetic layer provided between the third and second magnetic layers, a fourth non-magnetic layer provided between the fourth magnetic layer and the third magnetic layer, and a fifth non-magnetic layer provided between the second magnetic pole and the fourth magnetic layer.

Abstract: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes a first magnetic pole, a magnetic element including a first magnetic layer, and a coil. The controller is electrically connected to the magnetic element and the coil. The controller is configured to supply a recording current to the coil and supply an element current to the magnetic element. The recording current includes a first period of a first polarity, a second period of a second polarity, a third period that shifts from the first to second period, and a fourth period that shifts from the second to first period. The element current includes DC and AC components. The AC component in the first period is the same as the AC component in the second period, the AC component in the third period, and the AC component in the fourth period.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a third magnetic layer provided between the second magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first and second magnetic layers, a second non-magnetic layer provided between the second and third magnetic layers, a third non-magnetic layer provided between the first magnetic pole and the first magnetic layer, and a fourth non-magnetic layer provided between the third magnetic layer and the second magnetic pole. A first magnetic pole length is shorter than a second magnetic pole length. A first magnetic layer length is longer than a second magnetic layer length.

Abstract: According to one embodiment, a magnetic recording device for utilizing assisted magnetic recording includes a magnetic head, a first circuit, a second circuit, a third circuit, and a controller. The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, and a coil. The magnetic element is located between the first magnetic pole and the second magnetic pole. The magnetic element includes a first magnetic layer. The first circuit is configured to supply a coil current to the coil. The second circuit is configured to supply an element current to the magnetic element. The third circuit is configured to detect an electrical resistance of the magnetic element. The controller is configured to control the element current by controlling the second circuit based on the electrical resistance detected by the third circuit.

Abstract: A magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, and a magnetic member. The magnetic element is provided between the first and second magnetic poles, and includes a first magnetic layer. The magnetic member includes a first magnetic part. A second direction from the first magnetic part to the magnetic element crosses a first direction from the first to second magnetic pole. The first magnetic part includes a magnetic material including at least one of first to third materials. The first material includes at least one selected from the group consisting of Mn3Sn, Mn3Ge and Mn3Ga. The second material includes at least one selected from the group consisting of a cubic or tetragonal compound including Mn and Ni, a cubic alloy including ?-phase Mn, and a cubic alloy including Fe. The third material includes an antiferromagnet.

Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a fourth magnetic layer provided between the second magnetic pole and the third magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second and first magnetic layers, a third non-magnetic layer provided between the third and second magnetic layers, a fourth non-magnetic layer provided between the fourth magnetic layer and the third magnetic layer, and a fifth non-magnetic layer provided between the second magnetic pole and the fourth magnetic layer.

Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a first nonmagnetic layer provided between the first and second magnetic layers, a second nonmagnetic layer provided between the second magnetic layer and the second magnetic pole, and a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer. The first magnetic layer includes a first element including at least one of Fe, Co, or Ni. The second magnetic layer includes (Fe100-xCox)100-yEy. A second element E includes at least one selected from the group consisting of Cr, V, Mn, Yi, and Sc. The first magnetic layer does not include the second element.

Abstract: A magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic member, a second magnetic member provided between the first magnetic member and the second magnetic pole, a first layer provided between the first and second magnetic members, and a second layer provided between the second magnetic member and the second magnetic pole. The first magnetic member includes first magnetic regions and a first nonmagnetic region. The first nonmagnetic region is between the one of the first magnetic regions and the other one of the first magnetic regions.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic member, a second magnetic member provided between the first and second magnetic members, and a first layer provided between the first and second magnetic members, and including at least one selected from the group consisting of Cr, V, Mn, Ti and Sc. The first magnetic member includes first magnetic regions and a first non-magnetic region. A direction from one of the first magnetic regions toward another one of the first magnetic regions is along a first direction from the first magnetic pole toward the second magnetic pole. The first non-magnetic region is between the one of the first magnetic regions and the other one of the first magnetic regions.

Abstract: According to one embodiment, an evaluation method of a magnetic head is disclosed. The method can include acquiring an electrical signal obtained from a magnetic element when supplying a first alternating current to a coil of a magnetic head and supplying a second current to the magnetic element. The magnetic head includes a first magnetic pole, a second magnetic pole, and a coil. The magnetic element is provided between the first magnetic pole and the second magnetic pole, and includes a first magnetic layer. The method can include detecting a time required for a change of an electrical resistance of the magnetic element based on a time when a polarity of the first alternating current is reversed based on the electrical signal.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.

Abstract: According to one embodiment, a magnetic head includes a shield, a magnetic pole, a first magnetic layer provided between the shield and the magnetic pole, a second magnetic layer provided between the first magnetic layer and the magnetic pole, a third magnetic layer provided between the second magnetic layer and the magnetic pole, a first nonmagnetic layer provided between the shield and the first magnetic layer, a second nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, a third nonmagnetic layer provided between the second magnetic layer and the third magnetic layer, and a fourth nonmagnetic layer provided between the third magnetic layer and the magnetic pole. The first and third nonmagnetic layers include one of Cu, Ag, Au, Al, and Ti. The second and fourth nonmagnetic layers include one of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic member, a second magnetic member provided between the first magnetic member and the second magnetic pole, a first layer provided between the first and second magnetic members, and a second layer provided between the second magnetic member and the second magnetic pole. The first magnetic member includes first magnetic regions and a first nonmagnetic region. The first nonmagnetic region is between the one of the first magnetic regions and the other one of the first magnetic regions. The second magnetic member includes second magnetic regions and a second nonmagnetic region. The second nonmagnetic region is between the one of the second magnetic regions and the other one of the second magnetic regions.

Abstract: According to one embodiment, a magnetic recording device includes a magnetic head, and an electrical circuit. The magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and the second magnetic poles. The stacked body includes a first nonmagnetic layer, a first magnetic layer provided between the first nonmagnetic layer and the second magnetic pole, a first layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the first layer and the second magnetic pole, a second magnetic layer provided between the second nonmagnetic layer and the second magnetic pole, and a third nonmagnetic layer provided between the second magnetic layer and the second magnetic pole. The electrical circuit supplies, to the stacked body, a first current having a first orientation from the second magnetic pole toward the first magnetic pole.

Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second and first magnetic layers, a third non-magnetic layer provided between the third and second magnetic layers, and a fourth non-magnetic layer provided between the second magnetic pole and the third magnetic layer. A thickness of the first magnetic layer is thicker than a thickness of the second magnetic layer. A thickness of the third magnetic layer is thicker than the second layer thickness.

Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a fourth magnetic layer provided between the second magnetic pole and the third magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second and first magnetic layers, a third non-magnetic layer provided between the third and second magnetic layers, a fourth non-magnetic layer provided between the fourth magnetic layer and the third magnetic layer, and a fifth non-magnetic layer provided between the second magnetic pole and the fourth magnetic layer.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.

Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a third magnetic layer provided between the second magnetic layer and the second magnetic pole, a first nonmagnetic layer provided between the first and second magnetic layers, a second nonmagnetic layer provided between the second and third magnetic layers, and a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer. A first magnetic pole length of the first magnetic pole is less than a second magnetic pole length of the second magnetic pole. A first magnetic layer length of the first magnetic layer is greater than a second magnetic layer length of the second magnetic layer.

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

Abstract: According to one embodiment, a magnetic recording device includes a magnetic head, and an electrical circuit. The 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 magnetic layer, a second magnetic layer, a first layer provided between the first and second magnetic layers, and a first nonmagnetic layer provided between the first magnetic layer and the first layer. A change rate of an electrical resistance of the stacked body with respect to a change of a current density flowing in the stacked body has a first value when the current density is in a first range, a second value when the current density is in a second range, and a third value when the current density is in a third range.