MAGNETIC DETECTING DEVICE HAVING LAMINATED SEED LAYER

Abstract

A magnetic detecting device is provided. The magnetic detecting device includes a magnetoresistive effect part having a fixed magnetic layer, and a free magnetic layer which faces the fixed magnetic layer with a nonmagnetic material layer therebetween and which varies in magnetization by an external magnetic field. A seed layer is provided below the magnetoresistive effect part. The seed layer includes an Al layer laminated on an NiFeCr layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of one embodiment of a thin film magnetic head including a magnetic detecting device;

FIG. 2 is a partially enlarged schematic view showing a seed layer of the magnetic detecting device shown in FIG. 1, and a distribution chart showing the Al concentration and Co concentration of the seed layer;

FIG. 3 is a sectional view of one embodiment of a thin film magnetic head including a magnetic detecting device;

FIG. 4 is a partially enlarged schematic view showing a seed layer of the magnetic detecting device shown in FIG. 3 and a distribution chart showing the Al concentration of the seed layer;

FIG. 5 is a graph showing the relationship between the film thickness of a seed layer in each specimen of a single-layer seed (NiFeCr), a two-layer seed (NiFeCr/Al), and a three-layer seed (NiFeCr/Co/Al), and the minimum resistance value (min. Rs);

FIG. 6 is a graph showing the relationship between the film thickness of a seed layer in each specimen of a single-layer seed (NiFeCr), a two-layer seed (NiFeCr/Al), and a three-layer seed (NiFeCr/Co/Al), and the resistance changing rate (ΔR/R); and

FIG. 7 is an enlarged graph showing that the resistance changing rate (ΔR/R) on the axis of ordinate of FIG. 6 is narrowed to a range of 14.5 (%) to 15.9 (%).

Claims

1. A magnetic detecting device comprising: a magnetoresistive effect part having a fixed magnetic layer, and a free magnetic layer which faces the fixed magnetic layer with a nonmagnetic material layer therebetween and which varies in magnetization by an external magnetic field; anda seed layer provided below the magnetoresistive effect part,wherein the seed layer includes an Al layer laminated on an NiFeCr layer.

2. A magnetic detecting device comprising: a magnetoresistive effect part having a fixed magnetic layer, and a free magnetic layer which faces the fixed magnetic layer with a nonmagnetic material layer therebetween and which varies in magnetization by an external magnetic field; anda seed layer provided below the magnetoresistive effect part,wherein the seed layer includes a Co layer laminated on an NiFeCr layer, and an Al layer laminated on the Co layer.

3. The magnetic detecting device according to claim 1, wherein the seed layer has a film thickness of 38 Å or more and 50 Å or less.

4. The magnetic detecting device according to claim 3, wherein the Al layer has a film thickness of 4 Å or more and 8 Å or less.

5. The magnetic detecting device according to claim 4, wherein an antiferromagnetic layer constituting the magnetoresistive effect part is formed on the seed layer, and the fixed magnetic layer, the nonmagnetic intermediate layer, and the free magnetic layer are laminated on the antiferromagnetic layer.

6. A magnetic detecting device comprising: a magnetoresistive effect part having a fixed magnetic layer, and a free magnetic layer which faces the fixed magnetic layer with a nonmagnetic material layer therebetween and which varies in magnetization by an external magnetic field; anda seed layer provided below the magnetoresistive effect part,wherein the seed layer is formed mainly of NiFeCr, and the concentration of Al in a surface region of the seed layer is higher than the concentration of Al in the other regions of the seed layer.

7. A magnetic detecting device comprising: a magnetoresistive effect part having a fixed magnetic layer, and a free magnetic layer which faces the fixed magnetic layer with a nonmagnetic material layer therebetween and which varies in magnetization by an external magnetic field; anda seed layer provided below the magnetoresistive effect part,wherein a high-concentration Co region having a higher Co concentration than the other regions of the seed region and a high-concentration Al region provided above the high-concentration Co region and having a higher Al concentration than the other regions of the seed layer exist in a surface region of the seed layer.

8. The magnetic detecting device according to claim 7, wherein the seed layer is formed to have a film thickness of 38 Å or more and 50 Å or less.

9. The magnetic detecting device according to claim 8, wherein an antiferromagnetic layer constituting the magnetoresistive effect part is formed on the seed layer, and the fixed magnetic layer, the nonmagnetic intermediate layer, and the free magnetic layer are laminated on the antiferromagnetic layer.

10. The magnetic detecting device according to claim 2, wherein the seed layer has a film thickness of 38 Å or more and 50 Å or less.

11. The magnetic detecting device according to claim 10, wherein the Co layer is formed to have a film thickness of 4 Å or more and 6 Å or less.

12. The magnetic detecting device according to claim 11, wherein an antiferromagnetic layer constituting the magnetoresistive effect part is formed on the seed layer, and the fixed magnetic layer, the nonmagnetic intermediate layer, and the free magnetic layer are laminated on the antiferromagnetic layer.

12. The magnetic detecting device according to claim 6, wherein the seed layer is formed to have a film thickness of 38 Å or more and 50 Å or less.

13. The magnetic detecting device according to claim wherein an antiferromagnetic layer constituting the magnetoresistive effect part is formed on the seed layer, and the fixed magnetic layer, the nonmagnetic intermediate layer, and the free magnetic layer are laminated on the antiferromagnetic layer.