Magnetic thin film and magnetoresistance effect element having a heusler alloy layer containing an additive element

Abstract

A magnetic thin film has a layer which is formed of an alloy having a ordered crystal structure whose composition formula is represented by XYZ or X2YZ (where X is one or more than one of the elements selected from the group consisting of Co, Ir, Rh, Pt, and Cu, Y is one or more than one of the elements selected from the group consisting of V, Cr, Mn, and Fe, and Z is one or more than one of the elements selected the group consisting of Al, Si, Ge, As, Sb, Bi, In, Ti, and Pb). The alloy contains at least one additive element which is not included in the composition formula of the alloy and which has a Debye temperature that is equal to or less than 300K.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating the main portions of a thin-film magnetic head according to an embodiment of the present invention;

FIG. 2 is a view of the MR element illustrated in FIG. 1, viewed from the side of the air bearing surface;

FIG. 3A is a schematic diagram illustrating the arrangement of elements when a Heusler alloy has the L21 structure;

FIG. 3B is a schematic diagram illustrating the arrangement of elements when a Heusler alloy has the B2 structure;

FIG. 4 is a graph showing the relationship between the amount of the additive Ag and the saturation magnetization Ms of a magnetic thin film produced in Experiment 1, when the magnetic thin film is annealed at 300° C.;

FIG. 5 is a graph showing the relationship between the amount of the additive Ag and the saturation magnetization Ms of a magnetic thin film produced in Experiment 1, when the magnetic thin film is annealed at 320° C.;

FIG. 6 is a graph showing the relationship between the amount of the additive Ag and the saturation magnetization Ms of a magnetic thin film produced in Experiment 1, when the magnetic thin film is annealed at 350° C.;

FIG. 7 is a graph showing the relationship between the film thickness and the saturation magnetization Ms of a magnetic thin film produced in Experiment 2, when the amount of the additive Ag is 10 atomic %;

FIG. 8 is a graph showing the relationship between the film thickness and the saturation magnetization Ms of a magnetic thin film produced in Experiment 2, when the amount of the additive Ag is 15 atomic %;

FIG. 9 is a graph showing the relationship between the Debye temperature of the additive element and the regularization initiating temperature of a magnetic thin film produced in Experiment 3.

FIG. 10 is an exemplary plan view of a wafer on which the thin-film magnetic heads illustrated in FIG. 1 are formed;

FIG. 11 is an exemplary perspective view of a slider that includes the thin-film magnetic head illustrated in FIG. 1;

FIG. 12 is a perspective view of a head gimbal assembly that includes the slider illustrated in FIG. 10;

FIG. 13 is a diagram showing the essential parts of a hard disk drive that includes the head gimbal assembly illustrated in FIG. 12; and

FIG. 14 is a plan view of a hard disk drive that includes the head gimbal assembly illustrated in FIG. 12.

Claims

1. A magnetic thin film comprising: a layer which is formed of an alloy having a ordered crystal structure whose composition formula is represented by XYZ or X2YZ (where X is one or more than one of the elements selected from the group consisting of Co, Ir, Rh, Pt, and Cu, Y is one or more than one of the elements selected from the group consisting of V, Cr, Mn, and Fe, and Z is one or more than one of the elements selected the group consisting of Al, Si, Ge, As, Sb, Bi, In, Ti, and Pb),wherein said alloy contains at least one additive element which is not included in the composition formula of said alloy and which has a Debye temperature that is equal to or less than 300K.

2. The magnetic thin film according to claim 1, wherein an amount of said additive element is between 2 to 20 atomic % relative to said alloy.

3. The magnetic thin film according to claim 1, wherein said additive element is selected from the group consisting of As, Se, Y, Zr, Nb, Pd, Ag, Cd, In, Sn, Sb, Hf, Ta, Pt, Au, Hg, TI, Pb, Bi, and La.

4. The magnetic thin film according to claim 3, wherein said additive element is selected from the group consisting of Au, Ag, Pd, and Nb.

5. The magnetic thin film according to claim 1, wherein said crystal structure has a L21 structure, said structure indicating a preferential orientation of (220) plane, and having a lattice constant between 0.55 and 0.58 nm.

6. The magnetic thin film according to claim 1, wherein said crystal structure has a B2 structure, said structure indicating a preferential orientation of (110) plane, and having a lattice constant between 0.275 and 0.29 nm.

7. A magnetoresistance element comprising: a pinned layer whose magnetization direction is fixed;a free layer whose magnetization direction changes in accordance with an external magnetic field; anda non-magnetic spacer layer which is provided between said pinned layer and said free layer,wherein both of said pinned layer and said free layer, said pinned layer, or said free layer includes said magnetic thin film according to claim 1.

8. The magnetoresistance element according to claim 7, wherein said pinned layer has two ferromagnetic layers and a non-magnetic intermediate layer which is sandwiched therebetween.

9. A thin-film magnetic head comprising said magnetoresistance element according to claim 7.

10. A magnetic memory element comprising: a plurality of said magnetoresistance elements according to claim 7; anda wiring unit which is connected to said plurality of magnetoresistance elements, said wiring unit being adapted to selectively write information in any one of said magnetoresistance elements or to selectively read information from any one of said magnetoresistance elements.