Magnetic head with multilayer configuration between magnetic poles and magnetic recording device
According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first and the second magnetic poles. The magnetic element includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The fourth magnetic layer includes a first element and at least one of Fe, Co or Ni. The first element including at least one selected from the group consisting of Cr, V, Mn, Ti, N and Sc. The fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.
1. A magnetic head, comprising:
a first magnetic pole;
a second magnetic pole; and
a magnetic element provided between the first magnetic pole and the second magnetic pole,
the magnetic element 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 fourth magnetic layer provided between the third magnetic layer and the second magnetic pole,
a first non-magnetic layer provided between the first magnetic pole and the first magnetic layer,
a second non-magnetic layer provided between the first magnetic layer and the second magnetic layer,
a third non-magnetic layer provided between the second magnetic layer and the third magnetic layer,
a fourth non-magnetic layer provided between the third magnetic layer and the fourth magnetic layer, and
a fifth non-magnetic layer provided between the fourth magnetic layer and the second magnetic pole,
the fourth magnetic layer including a first element and at least one of Fe, Co or Ni, the first element including at least one selected from a group consisting of Cr, V, Mn, Ti, N and Sc,
the fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, and
the fifth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
wherein
the first magnetic layer, the second magnetic layer and the third magnetic layer include at least one of Fe, Co or Ni,
the first magnetic layer, the second magnetic layer, and the third magnetic layer do not include the first element, or a concentration of the first element in the first magnetic layer, the second magnetic layer, and the third magnetic layer is lower than a concentration of the first element in the fourth magnetic layer,
the first non-magnetic layer includes at least one selected from a group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
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,
a second thickness of the second magnetic layer in a first direction from the first magnetic pole to the second magnetic pole is thicker than a first thickness of the first magnetic layer in the first direction,
a third thickness of the third magnetic layer in the first direction is thicker than the first thickness, and
a fourth thickness of the fourth magnetic layer in the first direction is thinner than the third thickness.
2. The magnetic head according to claim 1 , wherein
the fourth non-magnetic layer contacts the fourth magnetic layer, and
the fifth non-magnetic layer contacts the fourth magnetic layer and the second magnetic pole.
3. The magnetic head according to claim 1 , wherein
one end of the magnetic element is electrically connected to the first magnetic pole,
another end of the magnetic element is electrically connected to the second magnetic pole, and
a differential electrical resistance of the magnetic element when changing a voltage between the first magnetic pole and the second magnetic pole includes at least one peak and at least one bottom.
4. A magnetic recording device, comprising:
the magnetic head according to claim 1 ; and
a controller including an element circuit,
one end of the magnetic element being electrically connected to the first magnetic pole,
another end of the magnetic element being electrically connected to the second magnetic pole,
the element circuit being configured to apply an element voltage between the first magnetic pole and the second magnetic pole,
when the element voltage is applied, a potential of the first magnetic pole is lower than a potential of the second magnetic pole.
5. The magnetic recording device according to claim 4 , wherein
a differential electrical resistance of the magnetic element when a voltage between the first magnetic pole and the second magnetic pole is changed includes at least one peak and at least one bottom,
the voltage corresponding to the at least one peak is a peak voltage,
the voltage corresponding to the at least one bottom is a bottom voltage, and
the element voltage is higher than the peak voltage and higher than the bottom voltage.
6. A magnetic head, comprising:
a first magnetic pole;
a second magnetic pole; and
a magnetic element provided between the first magnetic pole and the second magnetic pole,
the magnetic element 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 fourth magnetic layer provided between the third magnetic layer and the second magnetic pole,
a first non-magnetic layer provided between the first magnetic pole and the first magnetic layer,
a second non-magnetic layer provided between the first magnetic layer and the second magnetic layer,
a third non-magnetic layer provided between the second magnetic layer and the third magnetic layer,
a fourth non-magnetic layer provided between the third magnetic layer and the fourth magnetic layer, and
a fifth non-magnetic layer provided between the fourth magnetic layer and the second magnetic pole,
the fourth magnetic layer including a first element and at least one of Fe, Co or Ni, the first element including at least one selected from a group consisting of Cr, V, Mn, Ti, N and Sc,
the fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag, and
the fifth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
wherein
the first magnetic layer, the second magnetic layer and the third magnetic layer include at least one of Fe, Co or Ni,
the first magnetic layer, the second magnetic layer, and the third magnetic layer do not include the first element, or a concentration of the first element in the first magnetic layer, the second magnetic layer, and the third magnetic layer is lower than a concentration of the first element in the fourth magnetic layer,
the first non-magnetic layer includes at least one selected from a group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
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,
wherein
the fourth non-magnetic layer contacts the fourth magnetic layer, and
the fifth non-magnetic layer contacts the fourth magnetic layer and the second magnetic pole,
the magnetic element further includes a fifth magnetic layer and a sixth non-magnetic layer,
the fifth magnetic layer is provided between the third non-magnetic layer and the third magnetic layer, and
the sixth non-magnetic layer is provided between the fifth magnetic layer and the third magnetic layer.
7. The magnetic head according to claim 6 , wherein
the first non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the third non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the sixth non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
a second thickness of the second magnetic layer in a first direction from the first magnetic pole to the second magnetic pole is thicker than a first thickness of the first magnetic layer in the first direction,
a third thickness of the third magnetic layer in the first direction is thicker than the first thickness,
a fourth thickness of the fourth magnetic layer in the first direction is thinner than the third thickness, and
a fifth thickness of the fifth magnetic layer in the first direction is thinner than the third thickness.
8. The magnetic head according to claim 6 , wherein
the first non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the third non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
the sixth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
a first thickness of the first magnetic layer in a first direction from the first magnetic pole to the second magnetic pole is thicker than a second thickness of the second magnetic layer in the first direction,
a third thickness of the third magnetic layer in the first direction is thicker than the second thickness,
a fourth thickness of the fourth magnetic layer in the first direction is thinner than the third thickness, and
a fifth thickness of the fifth magnetic layer in the first direction is thinner than the third thickness.
9. The magnetic head according to claim 6 , wherein
the first non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the third non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
the sixth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
a second thickness of the second magnetic layer in a first direction from the first magnetic pole to the second magnetic pole is thicker than a first thickness of the first magnetic layer in the first direction,
a third thickness of the third magnetic layer in the first direction is thicker than the first thickness,
a fourth thickness of the fourth magnetic layer in the first direction is thinner than the third thickness, and
a fifth thickness of the fifth magnetic layer in the first direction is thinner than the third thickness.
10. The magnetic head according to claim 6 , wherein
the magnetic element further includes a sixth magnetic layer and a seventh non-magnetic layer,
the sixth magnetic layer is provided between the third non-magnetic layer and the fifth magnetic layer, and
the seventh non-magnetic layer is provided between the sixth magnetic layer and the fifth magnetic layer.
11. The magnetic head according to claim 10 , wherein
the first non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
the second non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the third non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the sixth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag,
the seventh non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W,
a second thickness of the second magnetic layer in a first direction from the first magnetic pole to the second magnetic pole is thicker than a first thickness of the first magnetic layer in the first direction,
a third thickness of the third magnetic layer in the first direction is thicker than the first thickness,
a fourth thickness of the fourth magnetic layer in the first direction is thinner than the third thickness,
a fifth thickness of the fifth magnetic layer in the first direction is thinner than the third thickness, and
a sixth thickness of the sixth magnetic layer in the first direction is thinner than the second thickness.
12. The magnetic head according to claim 6 , wherein
one end of the magnetic element is electrically connected to the first magnetic pole,
another end of the magnetic element is electrically connected to the second magnetic pole, and
a differential electrical resistance of the magnetic element when changing a voltage between the first magnetic pole and the second magnetic pole includes at least one peak and at least one bottom.
13. A magnetic recording device, comprising:
the magnetic head according to claim 6 ; and
a controller including an element circuit,
one end of the magnetic element being electrically connected to the first magnetic pole,
another end of the magnetic element being electrically connected to the second magnetic pole,
the element circuit being configured to apply an element voltage between the first magnetic pole and the second magnetic pole,
when the element voltage is applied, a potential of the first magnetic pole is lower than a potential of the second magnetic pole.
14. The magnetic recording device according to claim 13 , wherein
a differential electrical resistance of the magnetic element when a voltage between the first magnetic pole and the second magnetic pole is changed includes at least one peak and at least one bottom,
the voltage corresponding to the at least one peak is a peak voltage,
the voltage corresponding to the at least one bottom is a bottom voltage, and
the element voltage is higher than the peak voltage and higher than the bottom voltage.