US5493465A
Expired / Lapsed
US
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Magnetoresistance effect element and magnetic recording apparatus
Assignee: Toshiba Corp
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Filing: 1994-03-14
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Granted: 1996-02-20
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Expires: 2014-03-14
Abstract
Abstract A magnetoresistance effect element has a pair of ferromagnetic layers with a middle non-magnetic metallic layer interposed therebetween. The middle non-magnetic metallic layer has lamination structure of non-magnetic metallic thin films formed of at least two kinds of non-magnetic metallic materials. In the lamination structure of the non-magnetic metallic thin film, Fermi energies of the non-magnetic metallic thin films disposed on interface sides of the ferromagnetic layers has a value closer to a Fermi energy in a direction of spin whose electron spin dependent mean free path is long among Fermi energies of the ferromagnetic layers. A non-magnetic metallic thin film is disposed between such two non-magnetic metallic thin films. Difference in Fermi energy between non-magnetic metallic thin films made of two kinds of non-magnetic metallic materials is 0.5 eV or more. By the use of such a middle non-magnetic metallic layer, while the thickness thereof is as thin as possible, exchange coupling between ferromagnetic layers can be small. Thus, resistance change sensitivity can be enhanced.
Inventors
- 👤 Yuzo Kamiguchi
- 👤 Susumu Hashimoto
- 👤 Atsuhito Sawabe
- 👤 Hitoshi Iwasaki
- 👤 Masashi Sahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:41
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09; G01R33/093; B; B82; B82Y; B82Y25/00; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; H; H10; H10N; H10N50/00; H10N50/10
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
184 words
A magnetic recording apparatus comprising: a magnetic head having a magnetoresistance effect element comprising: at least one pair of ferromagnetic layers; said ferromagnetic layers having a first Fermi energy in a first electron spin direction and a second Fermi energy in a second electron spin direction, said first electron spin direction having a longer electron spin dependent mean free path than said second electron spin direction; a non-magnetic metallic layer disposed between and abutting against said ferromagnetic layers and having a laminated structure comprising at least a first type of non-magnetic metallic thin film, and a second type of non-magnetic metallic thin film, said first type of non-magnetic metallic thin film being adjacent to and abutting against said second type of non-magnetic metallic thin film, the Fermi energies of the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers being closer to said first Fermi energy of the ferromagnetic layers than said second Fermi energy of the ferromagnetic layers, and the difference in the Fermi energies of the different non-magnetic metallic thin films being 0.5 eV or more; and a magnetic record medium.
Claim 2
Dependent Claim
184 words
A magnetic recording apparatus comprising: a magnetic head having a magnetoresistance effect element comprising: at least one pair of ferromagnetic layers; said ferromagnetic layers having a first Fermi energy in a first electron spin direction and a second Fermi energy in a second electron spin direction, said first electron spin direction having a longer electron spin dependent mean free path than said second electron spin direction; a non-magnetic metallic layer disposed between and abutting against said ferromagnetic layers and having a laminated structure comprising at least a first type of non-magnetic metallic thin film, and a second type of non-magnetic metallic thin film, said first type of non-magnetic metallic thin film being adjacent to and abutting against said second type of non-magnetic metallic thin film, the Fermi energies of the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers being closer to said first Fermi energy of the ferromagnetic layers than said second Fermi energy of the ferromagnetic layers, and the difference in the Fermi energies of the different non-magnetic metallic thin films being 0.5 eV or more; and a magnetic record medium.
Claim 3
Dependent Claim
62 words
The magnetic recording apparatus of claim 1, wherein the middle non-magnetic metallic layer has three-layer lamination structure in which two non-magnetic metallic thin films of a first type are disposed adjacent to and abut against the ferromagnetic layers and a non-magnetic metallic thin film of a second type is interposed between and abuts against the two first type non-magnetic metallic thin films.
Claim 4
Dependent Claim
19 words
The magnetic recording apparatus of claim 1, wherein the different non-magnetic metallic thin films include eutectic or peritectic combinations.
Claim 5
Dependent Claim
31 words
The magnetic recording apparatus of claim 1, wherein one pair of the ferromagnetic layers comprise a ferromagnetic body whose main component is at least one element selected from CO and Ni.
Claim 6
Dependent Claim
38 words
The magnetic recording apparatus of claim 4, wherein the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers comprise a non-magnetic metallic material whose main component is at least one element selected from Cu, Au and Pt.
Claim 7
Dependent Claim
39 words
The magnetic recording apparatus of claim 1, wherein the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers have a Fermi energy which differs by 0.5 eV or less from the first Fermi energy of the ferromagnetic layers.
Claim 8
Dependent Claim
30 words
The magnetic recording apparatus of claim 1, wherein the different non-magnetic metallic thin films are at least one combination selected from Cu-Ag, Au-Ag, Pt-Ag, Cu-Pd, Au-Pd, Pt-Pd, Cu-Au and Pt-Au.
Claim 9
Dependent Claim
21 words
The magnetic recording apparatus of claim 1, wherein the middle non-magnetic metallic layer a thickness of 1 nm to 5 nm.
Claim 10
Dependent Claim
24 words
The magnetic recording apparatus of claim 1, wherein the non-magnetic metallic thin films each have a thickness ranging from 0.2 nm to 2 nm.
Claim 11
Dependent Claim
22 words
The magnetic recording apparatus of claim 1, wherein each of the ferromagnetic layers have a thickness of 1 nm to 20 nm.
Claim 12
Dependent Claim
171 words
A magnetoresistance effect element comprising: at least one pair of ferromagnetic layers; said ferromagnetic layers having a first Fermi energy in a first electron spin direction and a second Fermi energy in a second electron spin direction, said first electron spin direction having a longer electron spin dependent mean free path than said second electron spin direction; and a non-magnetic metallic layer disposed between and abutting against said ferromagnetic layers and having a laminated structure comprising at least a first type of non-magnetic metallic thin film, and a second type of non-magnetic metallic thin film, said first type of non-magnetic metallic thin film being adjacent to and abutting against said second type of non-magnetic metallic thin film, the Fermi energies of the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers being closer to said first Fermi energy of the ferromagnetic layers than said second Fermi energy of the ferromagnetic layers, and the difference in the Fermi energies of the different non-magnetic metallic thin films being 0.5 eV or more.
Claim 13
Dependent Claim
171 words
A magnetoresistance effect element comprising: at least one pair of ferromagnetic layers; said ferromagnetic layers having a first Fermi energy in a first electron spin direction and a second Fermi energy in a second electron spin direction, said first electron spin direction having a longer electron spin dependent mean free path than said second electron spin direction; and a non-magnetic metallic layer disposed between and abutting against said ferromagnetic layers and having a laminated structure comprising at least a first type of non-magnetic metallic thin film, and a second type of non-magnetic metallic thin film, said first type of non-magnetic metallic thin film being adjacent to and abutting against said second type of non-magnetic metallic thin film, the Fermi energies of the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers being closer to said first Fermi energy of the ferromagnetic layers than said second Fermi energy of the ferromagnetic layers, and the difference in the Fermi energies of the different non-magnetic metallic thin films being 0.5 eV or more.
Claim 14
Dependent Claim
62 words
The magnetoresistance effect element of claim 11, wherein the middle non-magnetic metallic layer has three-layer lamination structure in which two non-magnetic metallic thin films of a first type are disposed adjacent to and abut against the ferromagnetic layers and a non-magnetic metallic thin film of a second type is interposed between and abuts against the two first type non-magnetic metallic thin films.
Claim 15
Dependent Claim
19 words
The magnetoresistance effect element of claim 11, wherein the different non-magnetic metallic thin films include eutectic or peritectic combinations.
Claim 16
Dependent Claim
31 words
The magnetoresistance effect element of claim 11, wherein one pair of the ferromagnetic layers comprise a ferromagnetic body whose main component is at least one element selected from Co and Ni.
Claim 17
Dependent Claim
38 words
The magnetoresistance effect element of claim 14, wherein the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers comprise a non-magnetic metallic material whose main component is at least one element selected from Cu, Au and Pt.
Claim 18
Dependent Claim
39 words
The magnetoresistance effect element of claim 11, wherein the non-magnetic metallic thin films disposed adjacent to the ferromagnetic layers have a Fermi energy which differs by 0.5 eV or less from the first Fermi energy of the ferromagnetic layers.
Claim 19
Dependent Claim
30 words
The magnetoresistance effect element of claim 11, wherein the different non-magnetic metallic thin films are at least one combination selected from Cu-Ag, Au-Ag, Pt-Ag, Cu-Pd, Au-Pd, Pt-Pd, Cu-Au and Pt-Au.
Claim 20
Dependent Claim
21 words
The magnetoresistance effect element of claim 11, wherein the middle non-magnetic metallic layer a thickness of 1 nm to 5 nm.
Claim 21
Dependent Claim
24 words
The magnetoresistance effect element of claim 11, wherein the non-magnetic metallic thin films each have a thickness ranging from 0.2 nm to 2 nm.
Claim 22
Dependent Claim
22 words
The magnetoresistance effect element of claim 11, wherein each of the ferromagnetic layers have a thickness of 1 nm to 20 nm.
References Cited (Backward Citations)
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