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A spin valve thin-film magnetic element has an improved rate of change in resistance (ΔR/R) that can be used for a narrower magnetic track. The spin valve thin-film magnetic element has a laminate that include an antiferromagnetic layer, a pinned magnetic layer, a non-magnetic conductive layer

A spin valve thin-film magnetic element has an improved rate of change in resistance (ΔR/R) that can be used for a narrower magnetic track. The spin valve thin-film magnetic element has a laminate that include an antiferromagnetic layer, a pinned magnetic layer, a non-magnetic conductive layer, a free magnetic layer, a back layer, specular-reflection layers and a pair of electrode layers formed at the two sides of the laminate. Preferably the specular reflection layer includes an oxide, such as α-Fe 2 O 3 or NiO, or a half-metal Heusler alloy, such as NiMnSb or PtMnSb.

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1. A spin valve thin-film magnetic element comprising:a substrate;an antiferromagnetic layer disposed on the substrate;a pinned magnetic layer, a first magnetization direction of the pinned magnetic layer being fixed by an exchange coupling magnetic field with the antiferromagnetic layer;a first non

1. A spin valve thin-film magnetic element comprising:a substrate;an antiferromagnetic layer disposed on the substrate;a pinned magnetic layer, a first magnetization direction of the pinned magnetic layer being fixed by an exchange coupling magnetic field with the antiferromagnetic layer;a first non-magnetic conductive layer disposed between the pinned magnetic layer and a free magnetic layer;a pair of electrode layers configured to supply a sense current to the pinned magnetic layer, the first non-magnetic conductive layer, and the free magnetic layer;a bias layer aligning a second magnetization direction of the free magnetic layer in a direction substantially perpendicular to the first magnetization direction; anda specular-reflection layer, positioned further from the non-magnetic conductive layer than the free magnetic layer,wherein the free magnetic layer comprises a first free magnetic layer, a second free magnetic layer, and a second non-magnetic conductive layer disposed between the first and the second free magnetic layers, the second free magnetic layer having a thickness in the range of approximately 30 angstroms to approximately 40 angstroms, and the first free magnetic layer having a thickness in the range of approximately 5 angstroms to approximately 25 angstroms. 2. A spin valve thin-film magnetic element according to claim 1, wherein the antiferromagnetic layer comprises one of an X—Mn alloy and a Pt—Mn—X′ alloy, in which X is one element selected from the group consisting of Pt, Pd, Ir, Rh, Ru, and Os, and X′ is at least one element selected from the group consisting of Pd, Cr, Ru, Ni, Ir, Rh, Os, Au, Ag, Ne, Ar, Xe, and Kr. 3. A spin valve thin-film magnetic element according to claim 1, wherein the specular-reflection layer comprises an insulating material configured to generate an energy gap having a high probability of producing specular reflection which conserves spin states of the conduction electrons. 4. A spin valve thin-film magnetic element according to claim 3, wherein the specular-reflection layer comprises an oxide. 5. A spin valve thin-film magnetic element according to claim 3, wherein the specular-reflection layer comprises one of α-Fe 2 O 3 and NiO. 6. A spin valve thin-film magnetic element according to claim 1, wherein a thickness of the specular-reflection layer is within the range of about 10 to about 400 Å. 7. A spin valve thin-film magnetic element according to claim 6, wherein the film thickness of the specular-reflection layer is within the range of about 10 to about 200 Å. 8. A spin valve thin-film magnetic element according to claim 1, wherein at least the antiferromagnetic layer directly underlies the pinned magnetic layer that underlies the first non-magnetic conductive layer that directly underlies the free magnetic layer that directly underlies the specular-reflection layer. 9. A spin valve thin-film magnetic element according to claim 1, wherein the free magnetic layer and the specular-reflection layer are separated by a back layer, comprising a non-magnetic conductive material. 10. A spin valve thin-film magnetic element according to claim 9, wherein the back layer comprises a material comprising an element selected from the group consisting of Au, Ag, and Cu. 11. A spin valve thin-film magnetic element according to claim 9, wherein a film thickness of the back layer is within the range of about 5 to about 15 Å. 12. A spin valve thin-film magnetic element according to claim 1, wherein the pinned magnetic layer is a multilayer film, and at least one layer of the multilayer film comprises a half-metal Heusler alloy. 13. A spin valve thin-film magnetic element according to claim 1, wherein the pinned magnetic layer comprises a first pinned magnetic layer, a second pinned magnetic layer, and a non-magnetic interlayer disposed therebetween, and the first and the second pinned magnetic layers are in a ferrimagnetic stat e having magnetization directions antiparallel to each other. 14. A spin valve thin-film magnetic head according to claim 1, wherein the free magnetic layer and the specular-reflection layer are separated by a back layer and a portion of the pair of electrode layers is directly adjacent to an upper surface of the back layer. 15. A spin valve thin-film magnetic element according to claim 14, wherein the pair of electrode layers is located further from the substrate than the antiferromagnetic layer. 16. A spin valve thin-film magnetic element according to claim 1, wherein at least the antiferromagnetic layer, the pinned magnetic layer, the free magnetic layer, and the specular-reflection layer comprise a laminate, and the pair of electrode layers is provided at the two sides of the laminate and extend toward the laminate in direct contact with the free magnetic layer. 17. A spin valve thin-film magnetic element according to claim 9, wherein at least the antiferromagnetic layer, the pinned magnetic layer, the free magnetic layer, and the specular-reflection layer comprise a laminate, and the pair of electrode layers is provided at two sides of the laminate and extend toward the laminate in direct contact with the back layer. 18. A spin valve thin-film magnetic element according to claim 10, wherein a thickness of the back layer is in the range of about 5 to about 15 Å. 19. A spin valve thin-film magnetic element according to claim 12, wherein the half-metal Heusler alloy comprises at least one of NiMnSb and PtMnSb, and the layer comprising the half-metal Heusler alloy is one of a monolayer film and a multilayer film. 20. A spin valve thin-film magnetic element comprising:a substrate;an antiferromagnetic layer disposed on the substrate;a pinned magnetic layer comprising a non-magnetic interlayer disposed between a first and a second pinned layer, the first pinned layer positioned in contact with the antiferromagnetic layer, a first magnetization direction of the first pinned magnetic layer being fixed by an exchange coupling magnetic field with the antiferromagnetic layer, the second pinned layer comprising a lower pinned layer and an upper pinned layer having a specular layer disposed therebetween;a first non-magnetic conductive layer disposed between the pinned magnetic layer and a free magnetic layer, the free magnetic layer comprising a first free magnetic layer, a second free magnetic layer, and a second non-magnetic conductive layer disposed between the first and the second free magnetic layers, the second free magnetic layer having a thickness in the range of approximately 30 angstroms to approximately 40 angstroms, and the first free magnetic layer having a thickness in the range of approximately 5 angstroms to approximately 25 angstroms; a pair of electrode layers configured to supply a sense current to the pinned magnetic layer, the first non-magnetic conductive layer, and the free magnetic layer, anda bias layer aligning the second magnetization direction in a direction substantially perpendicular to the first magnetization direction; andwherein the specular-reflection layer comprises a multilayer film, one layer of the multilayer film further comprising a half-metal Heusler alloy. 21. A spin valve thin-film magnetic element according to claim 20, wherein the half-metal Heusler alloy comprises at least one of NiMnSb and PtMnSb, and the layer comprising the half-metal Heusler alloy is one of a monolayer film and a multilayer film. 22. A spin valve thin-film magnetic element comprising:an antiferromagnetic layer;a pinned magnetic layer coupled to the antiferromagnetic layer, a magnetization direction of the pinned magnetic layer being fixed by an exchange coupling magnetic field with the antiferromagnetic layer;a non-magnetic conductive layer disposed between the pinned magnetic layer and a free magnetic layer;a pair of electrodes configured to supply a current to the pinned magnetic layer, the non-magnetic conduct ive layer, and the free magnetic layer;a specular-reflection layer comprised of a half-metal Heusler alloy positioned further from the non-magnetic conductive layer than the free magnetic layer; anda bias layer aligning the magnetization direction of the free magnetic layer to the magnetization direction of the pinned magnetic layer. 23. A spin valve thin-film magnetic element comprising:a substrate;an antiferromagnetic layer disposed on the substrate;a pinned magnetic layer in contact with the antiferromagnetic layer, a first magnetization direction of the pinned magnetic layer being fixed by an exchange coupling magnetic field with the antiferromagnetic layer;a non-magnetic conductive layer disposed between the pinned magnetic layer and a free magnetic layer;a pair of electrode layers configured to supply a sense current to the pinned magnetic layer, the non-magnetic conductive layer, and the free magnetic layer;a bias layer aligning a second magnetization direction of the free magnetic layer in a direction substantially perpendicular to the first magnetization direction; anda specular-reflection layer, positioned further from the non-magnetic conductive layer than the free magnetic layer;wherein the specular-reflection layer comprises an insulating material that comprises a half-metal Heusler alloy. 24. A spin valve thin-film magnetic element according to claim 23, wherein the half-metal Heusler alloy comprises at least one of NiMnSb and PtMnSb, and the specular-reflection layer is one of a monolayer film and a multilayer film. 25. A spin valve thin-film magnetic element comprising:a substrate;an antiferromagnetic layer disposed on the substrate;a pinned magnetic layer being in contact with the antiferromagnetic layer, a first magnetization direction of the pinned magnetic layer being fixed by an exchange coupling magnetic field with the antiferromagnetic layer;a first non-magnetic conductive layer disposed between the pinned magnetic layer and a free magnetic layer, the free magnetic layer comprising a first free magnetic layer, a second free magnetic layer, and a second non-magnetic conductive layer disposed between the first and the second free magnetic layers, the second free magnetic layer having a thickness in the range of approximately 30 angstroms to approximately 40 angstroms, and the first free magnetic layer having a thickness in the range of approximately 5 angstroms to approximately 25 angstroms;a pair of electrode layers configured to supply a sense current to the pinned magnetic layer; the first non-magnetic conductive layer, and the free magnetic layer; anda bias layer aligning a second magnetization direction of the free magnetic layer in a direction substantially perpendicular to the first magnetization direction.