Magnetic head and magnetic recording device
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.
1. A magnetic head comprising:
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 including
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 magnetic layer and the first magnetic layer,
a third non-magnetic layer provided between the third magnetic layer and the second magnetic layer,
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,
the second non-magnetic layer contacting the second magnetic layer and the first magnetic layer,
the third non-magnetic layer contacting the third magnetic layer and the second magnetic layer, and
the fourth non-magnetic layer contacting the fourth magnetic layer and the third magnetic layer.
2. The head according to claim 1 , wherein
the first non-magnetic layer contacts the first magnetic layer and the first magnetic pole.
3. The head according to claim 2 , wherein
the fifth non-magnetic layer contacts the second magnetic pole and the fourth magnetic layer.
4. The head according to claim 1 , wherein
the fifth non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W.
5. The head according to claim 4 , wherein
The first non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.
6. The head according to claim 3 , wherein
the fourth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.
7. The head according to claim 1 , wherein
the second non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W, and the third non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, or
the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, and the third non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W.
8. The head according to claim 1 , wherein
a third thickness of the third magnetic layer along a first direction from the first magnetic pole toward the second magnetic pole is not less than 0.5 times and not more than 1.5 times a first thickness of the first magnetic layer along the first direction.
9. The head according to claim 8 , wherein
the third thickness is not less than 0.8 times and not more than 1.25 times the first thickness.
10. The head according to claim 8 , wherein
a fourth thickness of the fourth magnetic layer along the first direction is less than the first thickness, and
the fourth thickness is less than the third thickness.
11. The head according to claim 8 , wherein
a fourth thickness of the fourth magnetic layer along the first direction is not more than 0.7 times the first thickness, and
the fourth thickness is not more than 0.7 times the third thickness.
12. The head according to claim 8 , wherein
a second thickness of the second magnetic layer along the first direction is less than the first thickness, and
the second thickness is less than the third thickness.
13. The head according to claim 8 , wherein
a second thickness of the second magnetic layer along the first direction is not more than 0.75 times the first thickness, and
the second thickness is not more than 0.75 times the third thickness.
14. The head according to claim 8 , wherein
a fourth thickness of the fourth magnetic layer along the first direction is not more than 1.5 times a second thickness of the second magnetic layer along the first direction.
15. The head according to claim 8 , wherein
a fourth thickness of the fourth magnetic layer along the first direction is not more than a second thickness of the second magnetic layer along the first direction.
16. The head according to claim 8 , wherein
a thickness of the second magnetic layer along the first direction is not less than 1 nm and not more than 8 nm.
17. The head according to claim 8 , wherein
a thickness of the fourth magnetic layer along the first direction is not less than 1 nm and not more than 5 nm.
18. The head according to claim 8 , wherein
the first thickness is not less than 5 nm and not more than 15 nm, and
the third thickness is not less than 5 nm and not more than 15 nm.
19. A magnetic recording device, comprising:
the magnetic head according to claim 1 ; and
an electric circuit,
the electric circuit is configured to supply a current to the stacked body, and
the current has a direction from the first magnetic layer toward the second magnetic layer.
20. The magnetic recording device according to claim 19 , wherein
when the electric circuit supplies the current to the stacked body,
an alternating magnetic field is generated from the stacked body.