US 5,493,465 A · Magnetoresistance effect element and magnetic recording apparatus

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.

Claims20

Dependent claims

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.

3 more elements

Dependencies are inferred from the claim text.

Magnetoresistance effect element and magnetic recording apparatus

Life of this patent

Magnetoresistance effect element and magnetic recording apparatus

Life of this patent

Abstract

Claims20