Back to results
US 6,645,646 B1Granted
Magnetic recording medium and magnetic storage apparatus
AssigneeFujitsu Limited
InventorsHisashi Umeda, E. Noel Abarra, Iwao Okamoto, Yoshifumi Mizoshita
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium is constructed to include at least one exchange layer structure and a magnetic layer provided on the exchange layer structure, where the exchange layer structure includes a ferromagnetic layer and a non-magnetic coupling layer provided on the ferromagnetic layer, and a magnetic bonding layer provided between the ferromagnetic layer and the non-magnetic coupling layer and/or between the non-magnetic coupling layer and the magnetic layer, wherein the magnetic bonding layer has a magnetization direction parallel to the ferromagnetic layer and the magnetic layer.
Claims26
A magnetic recording medium comprising:
- at least one exchange layer structure and a magnetic layer provided on the exchange layer structure, said exchange layer structure including a ferromagnetic layer and a non-magnetic coupling layer provided on the ferromagnetic layer;
- a lower magnetic bonding layer provided between the ferromagnetic layer and the non-magnetic coupling layer;
- and
- an upper magnetic bonding layer provided between the non-magnetic coupling layer and the magnetic layer,
- wherein said upper and lower magnetic bonding layers are made of a material selected from a group consisting of Fe, Fe alloys, Ni alloys, and Co alloys,
- said upper and lower magnetic bonding layers have magnetization directions respectively parallel to the ferromagnetic layer and the magnetic layer, and
- a Co or Fe concentration of the upper magnetic bonding layer is higher than that of the magnetic layer, and a Co or Fe concentration of the lower magnetic bonding layer is higher than that of the ferromagnetic layer, so that an exchange coupling between the upper and lower magnetic bonding layers is larger than an exchange coupling between the magnetic layer and the ferromagnetic layer.
4 more elements
A magnetic recording medium comprising:
- at least one exchange layer structure and a magnetic layer provided on the exchange layer structure, said exchange layer structure including a ferromagnetic layer and a non-magnetic coupling layer provided on the ferromagnetic layer;
- a lower magnetic bonding layer provided between the ferromagnetic layer and the non-magnetic coupling layer;
- and
- an upper magnetic bonding layer provided between the non-magnetic coupling layer and the magnetic layer,
- said upper and lower magnetic bonding layers having magnetization directions respectively parallel to the ferromagnetic layer and the magnetic layer,
- an exchange coupling between the upper and lower magnetic bonding layers being larger than an exchange coupling between the magnetic layer and the ferromagnetic layer,
- wherein said at least one exchange layer structure includes at least a first exchange layer structure and a second exchange layer structure provided between the first exchange layer structure and the magnetic layer, said second exchange layer structure having a ferromagnetic layer with a magnetic anisotropy smaller than that of a ferromagnetic layer of the first exchange layer structure, said first and second exchange layer structure having ferromagnetic layers with magnetization directions which are mutually antiparallel.
4 more elements
A magnetic storage apparatus comprising:
- at least one magnetic recording medium including at least one exchange layer structure and a magnetic layer provided on the exchange layer structure, said exchange layer structure including a ferromagnetic layer and a non-magnetic coupling layer provided on the ferromagnetic layer,
- a lower magnetic bonding layer provided between the ferromagnetic layer and the non-magnetic coupling layer, and an upper magnetic bonding layer provided between the non-magnetic coupling layer and the magnetic layer,
- wherein said upper and lower magnetic bonding layers are made of a material selected from a group consisting of Fe, Fe alloys, Ni alloys, and Co alloys,
- said upper and lower magnetic bonding layers have magnetization directions respectively parallel to the ferromagnetic layer and the magnetic layer, and
- a Co or Fe concentration of the upper magnetic bonding layer is higher than that of the magnetic layer, and a Co or Fe concentration of the lower magnetic bonding layer is higher than that of the ferromagnetic layer, so that an exchange coupling between the upper and lower magnetic bonding layers is larger than an exchange coupling between the magnetic layer and the ferromagnetic layer.
2 more elements
A magnetic recording medium comprising:
- at least one exchange layer structure and a magnetic layer provided on the exchange layer structure, said exchange layer structure including a ferromagnetic layer and a non-magnetic coupling layer provided on the ferromagnetic layer;
- and
- a magnetic bonding layer provided between the ferromagnetic layer and the non-magnetic coupling layer,
- wherein said magnetic bonding layer is made of a material selected from a group consisting of Fe, Fe alloys, Ni alloys and Co alloys,
- said magnetic bonding layer has a Co or Fe concentration higher than that of the ferromagnetic layer.
2 more elements
A magnetic recording medium comprising:
- at least one exchange layer structure and a magnetic layer provided on the exchange layer structure, said exchange layer structure including a ferromagnetic layer and a non-magnetic coupling layer provided on the ferromagnetic layer;
- and
- a magnetic bonding layer provided between the magnetic layer and the non-magnetic coupling layer,
- wherein said magnetic bonding layer is made of a material selected from a group consisting of Fe, Fe alloys, Ni alloys and Co alloys,
- said magnetic bonding layer has a Co or Fe concentration higher than that of the magnetic layer.
2 more elements
Dependencies are inferred from the claim text.