Magnetic head including multiple magnetic layers and magnetic recording device
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.
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 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 magnetic layer and the second magnetic layer,
a second non-magnetic layer provided between the second magnetic layer and the third magnetic layer,
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,
the fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Al, V and Ag,
the third magnetic layer including (F 100-x Co x ) 100-y E y (TO atomic %≤x≤50 atomic %, 10 atomic %≤y≤90 atomic %), a second element E including at least one selected from the group consisting of Cr, V, Mn, Ti and Sc,
a first magnetic pole length of the first magnetic pole along a second direction being shorter than a second magnetic pole length of the second magnetic pole along the second direction, the second direction being perpendicular to a first direction from the first magnetic layer to the second magnetic layer, and being along a medium-facing surface of the first magnetic pole, and
a first magnetic layer length of the first magnetic layer along a third direction being longer than a second magnetic layer length of the second magnetic layer along the third direction, the third direction being perpendicular to the first direction.
2. The head according to claim 1 , wherein
the third direction is along the second direction.
3. The head according to claim 1 , wherein
the first magnetic layer includes at least one of Fe, Co or Ni, and
the second magnetic layer includes at least one of Fe, Co or Ni.
4. The head according to claim 1 , wherein
the third direction crosses the second direction.
5. The head according to claim 4 , wherein
the first direction is inclined with respect to the medium-facing surface.
6. The magnetic head according to claim 1 , wherein
the composition ratio x is not less than 25 atomic % and not more than 35 atomic %.
7. The head according to claim 6 , wherein
the composition ratio y is not less than 10 atomic % and not more than 30 atomic %.
8. The head according to claim 1 , wherein
the first non-magnetic layer includes at least one first element selected from the group consisting of Ru, Ir, Ta and W, and
a thickness of the first non-magnetic layer along the first direction is not less than 0.2 nm and not more than 3 nm.
9. The head according to claim 1 , wherein
a first product of a first magnetic layer thickness of the first magnetic layer along the first direction and a saturation magnetization of the first magnetic layer is not less than 0.8 times and not more than 1.25 times a second product of a second magnetic layer thickness of the second magnetic layer along the first direction and a saturation magnetization of the second magnetic layer.
10. The head according to claim 1 , wherein
a third magnetic layer thickness along the first direction of the third magnetic layer is not more than 0.7 times a first magnetic layer thickness of the first magnetic layer along the first direction, and not more than 0.7 times a second magnetic layer thickness of the second magnetic layer along the first direction.
11. The head according to claim 10 , wherein
the second magnetic layer thickness is not less than 0.8 times and not more than 1.25 times the first magnetic layer thickness.
12. The head according to claim 1 , wherein
the second non-magnetic layer and the third non-magnetic layer include at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.
13. A magnetic recording device, comprising:
the magnetic head according to claim 1 ; and
an electric circuit,
the electric circuit being configured to supply a current to the stacked body, and
the current having an orientation from the first magnetic layer to the second magnetic layer.
14. 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 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 non-magnetic layer provided between the second magnetic layer and the first magnetic layer,
a second non-magnetic layer provided between the third magnetic layer and the second magnetic layer,
a third non-magnetic layer provided between the first magnetic layer and the second magnetic pole, and
a fourth non-magnetic layer provided between the third magnetic layer and the first magnetic pole,
the fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Al, V and Ag,
the third magnetic layer including (Fe 100-x Co x ) 100-y E y (10 atomic %≤x≤50 atomic %, 10 atomic %≤y≤90 atomic %), a second element E including at least one selected from the group consisting of Cr, V, Mn, Ti and Sc,
a first magnetic pole length of the first magnetic pole along a second direction being shorter than a second magnetic pole length of the second magnetic pole along the second direction, the second direction being perpendicular to a first direction from the second magnetic layer to the first magnetic layer, and being along a medium-facing surface of the first magnetic pole, and
a second magnetic layer length of the second magnetic layer along a third direction being longer than a first magnetic layer length of the first magnetic layer along the third direction, the third direction being perpendicular to the first direction.
15. The head according to claim 14 , wherein
the third direction is along the second direction.
16. The head according to claim 14 , wherein
the first magnetic layer includes at least one of Fe, Co or Ni, and
the second magnetic layer includes at least one of Fe, Co or Ni.
17. The head according to claim 14 , wherein
the third direction crosses the second direction.
18. The head according to claim 17 , wherein
the first direction is inclined with respect to the medium-facing surface.