Magnetic head and magnetic recording device

A magnetic head, comprising:

• a shield;
• a magnetic pole;
• a first magnetic layer provided between the shield and the magnetic pole;
• a second magnetic layer provided between the shield and the first magnetic layer;
• a third magnetic layer provided between the shield and the second magnetic layer;
• a first nonmagnetic layer provided between the first magnetic layer and the magnetic pole;
• a second nonmagnetic layer provided between the second magnetic layer and the first nonmagnetic layer;
• a third nonmagnetic layer provided between the third magnetic layer and the second nonmagnetic layer;
• and
• a fourth nonmagnetic layer provided between the shield and the third magnetic layer,
• the first nonmagnetic layer and the third nonmagnetic layer including at least one selected from the group consisting of Cu, Ag, Au, Al, and Ti,
• the second nonmagnetic layer and the fourth nonmagnetic layer including at least one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru,
• thicknesses along a first direction of the second nonmagnetic layer and the fourth nonmagnetic layer each being not less than 1 nm and not more than 3 nm, the first direction being from the shield toward the magnetic pole.

A magnetic head, comprising:

• a shield;
• a magnetic pole having a medium-opposing surface, a first direction from the shield toward the magnetic pole being along the medium-opposing surface;
• a first magnetic layer, a position in the first direction of the first magnetic layer being between a position in the first direction of the shield and a position in the first direction of the magnetic pole;
• a second magnetic layer provided between the shield and the magnetic pole, a position of the second magnetic layer in a second direction being between a position in the second direction of the first magnetic layer and a position in the second direction of a plane including the medium-opposing surface, the second direction crossing the medium-opposing surface;
• a third magnetic layer provided between the second magnetic layer and the magnetic pole;
• a first nonmagnetic layer provided between the first magnetic layer and the magnetic pole;
• a second nonmagnetic layer provided between the shield and the second magnetic layer;
• a third nonmagnetic layer provided between the second magnetic layer and the third magnetic layer;
• a fourth nonmagnetic layer provided between the third magnetic layer and the magnetic pole;
• a fifth nonmagnetic layer, the first magnetic layer being provided between the fifth nonmagnetic layer and the first nonmagnetic layer;
• and
• a sixth nonmagnetic layer provided between the second nonmagnetic layer and the second magnetic layer.

A magnetic head, comprising:

• a shield;
• a magnetic pole having a medium-opposing surface, a first direction from the shield toward the magnetic pole being along the medium-opposing surface;
• a first magnetic layer, a position in the first direction of the first magnetic layer being between a position in the first direction of the shield and a position in the first direction of the magnetic pole;
• a second magnetic layer provided between the shield and the magnetic pole, a position of the second magnetic layer in a second direction being between a position in the second direction of the first magnetic layer and a position in the second direction of a plane including the medium-opposing surface, the second direction crossing the medium-opposing surface;
• a third magnetic layer provided between the shield and the second magnetic layer;
• a first nonmagnetic layer provided between the first magnetic layer and the magnetic pole;
• a second nonmagnetic layer provided between the second magnetic layer and the magnetic pole;
• a third nonmagnetic layer provided between the third magnetic layer and the second magnetic layer;
• a fourth nonmagnetic layer provided between the shield and the third magnetic layer;
• a fifth nonmagnetic layer, the first magnetic layer being provided between the fifth nonmagnetic layer and the first nonmagnetic layer;
• and
• a sixth nonmagnetic layer provided between the second magnetic layer and the second nonmagnetic layer.

A magnetic recording device, comprising:

• 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;
• a fourth nonmagnetic layer provided between the third magnetic layer and the magnetic pole;
• and
• a circuit portion including a first circuit and a second circuit, the first circuit being configured to supply a first current having an orientation from the first nonmagnetic layer toward the second nonmagnetic layer, the second circuit being configured to supply a second current having an orientation from the second nonmagnetic layer toward the fourth nonmagnetic layer,
• the circuit portion being configured to control the first current and the second current independently from each other.

A magnetic recording device, comprising:

• 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 first magnetic layer and the second magnetic layer;
• 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 third magnetic layer;
• a third nonmagnetic layer provided between the third magnetic layer and the second magnetic layer;
• a fourth nonmagnetic layer provided between the second magnetic layer and the magnetic pole;
• and
• a circuit portion including a first circuit and a second circuit, the first circuit being configured to supply a first current having an orientation from the first nonmagnetic layer toward the second nonmagnetic layer, the second circuit being configured to supply a second current having an orientation from the fourth nonmagnetic layer toward the second nonmagnetic layer,
• the circuit portion being configured to control the first current and the second current independently from each other.