MAGNETO-RESISTIVE EFFECT DEVICE, MAGNETIC HEAD GIMBAL ASSEMBLY, MAGNETIC RECORDING/REPRODUCTION DEVICE, STRAIN SENSOR, PRESSURE SENSOR, BLOOD PRESSURE SENSOR, AND STRUCTURAL HEALTH MONITORING SENSOR

• US 20150185296A1
• Filed: 03/17/2015
• Published: 07/02/2015
• Est. Priority Date: 03/24/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: GIDDINGS, Devin, Fukuzawa, Hideaki, Fuji, Yoshihiko, Hara, Michiko, Yuasa, Hiromi
• Granted Patent: US 9,435,868 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: G01R 33/091 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11B 5/399 with intrinsic biasing, e.g. provided by equipotential strips
• CPC Class Codes: H01F 10/30 characterised by the composition of the intermediate layers , e.g. seed, buffer, template, diffusion preventing, cap layers H01F10/06 and H01F10/32 take precedence
• CPC Class Codes: H01F 10/325 the spacer being noble metal
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3259 Spin-exchange-coupled multilayers comprising at least a nanooxide layer [NOL], e.g. with a NOL spacer
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

According to one embodiment, a magneto-resistive effect device, includes a stacked body stacked on a substrate, a pair of first electrodes that feeds current to the stacked body, a strain introduction member, and a second electrode for applying a voltage to the strain introduction member. The stacked body includes a first magnetic layer that includes one or more metals selected from the group consisting of iron, cobalt, and nickel, a second magnetic layer stacked on the first magnetic layer, having a composition that is different from the first magnetic layer, and a spacer layer disposed between the first magnetic layer and the second magnetic layer.

Claims

1. A magneto-resistive effect device, comprising

a stacked body stacked on a substrate, the stacked body including

a first magnetic layer that includes one or more metals selected from the group consisting of iron, cobalt, and nickel,

a second magnetic layer stacked on the first magnetic layer, having a composition that is different from the first magnetic layer, and

a spacer layer disposed between the first magnetic layer and the second magnetic layer;

a pair of first electrodes that feeds current to the stacked body;

a strain introduction member that applies strain to the stacked body, that is provided near the stacked body, and by applying strain to the stacked body, biases magnetization directions of the first magnetic layer and the second magnetic layer in different directions; and

a second electrode for applying a voltage to the strain introduction member, wherein

the magnetization directions of the first magnetic layer and the second magnetic layer are changed by the application of an external magnetic field, and

the external magnetic field is detected by a change in resistance between the first electrodes due to the change in the magnetization directions.

2. The device according to claim 1, wherein the first magnetic layer has a positive magnetostriction coefficient, and the second magnetic layer has a negative magnetostriction coefficient.

3. The device according to claim 1, wherein the strain introduction member is disposed to the side of a film cross-section of the stacked body.

4. The device according to claim 1, wherein the strain introduction member includes one material selected from the group consisting of crystalline silicon oxide (SiO₂), zinc oxide (ZnO), KaC₄H₄O₆, lead zirconate titanate (PZT:

Pb(Zr, Ti)O₃), lithium niobate (LiNbO₃), lithium tantalate (LiTaO₃), lithium borate (Li₂B₄O₇), langasite (La₃Ga₅SiO₁₄), aluminum nitride (AlN), polyvinylidene difluoride (PVDF), gallium phosphate (GaPO₄), and tourmaline.

5. The device according to claim 1, wherein the strain introduction member either directly contacts the stacked body, or contacts via an insulating material made from amorphous SiO₂ or amorphous Al₂O₃.

6. The device according to claim 1, wherein an electrode is provided at about 45 degrees or 135 degrees to the strain introduction member when viewed from the direction of application of the external magnetic field, in order to apply a strain to the stacked body.

7. The device according to claim 1, wherein the first magnetic layer includes an oxide of one metal selected from the group consisting of iron, cobalt, and nickel.

8. The device according to claim 1, wherein the second magnetic layer includes one or more metals selected from the group consisting of nickel and samarium iron (SmFe).

9. The device according to claim 1, wherein the spacer layer includes an oxide or a nitride of one metal selected from the group consisting of aluminum, titanium, zinc, silicon, hafnium, tantalum, moylbdenum, tungsten, niobium, chromium, magnesium, and zirconium.

10. A magnetic head gimbal assembly, comprising:

a magneto-resistive effect device, wherein,

the magneto-resistive effect device includes;

a stacked body stacked on a substrate, the stacked body including

a first magnetic layer that includes one or more metals selected from the group consisting of iron, cobalt, and nickel,

a second magnetic layer stacked on the first magnetic layer, having a composition that is different from the first magnetic layer, and

a spacer layer disposed between the first magnetic layer and the second magnetic layer;

a pair of first electrodes that feeds current to the stacked body;

a strain introduction member that applies strain to the stacked body, that is provided near the stacked body, and by applying strain to the stacked body, biases magnetization directions of the first magnetic layer and the second magnetic layer in different directions; and

a second electrode that applies a voltage to the strain introduction member, wherein

the magnetization directions of the first magnetic layer and the second magnetic layer are changed by the application of an external magnetic field, and

the external magnetic field is detected by a change in resistance between the first electrodes due to the change in the magnetization directions.

11. A magnetic recording/reproduction device, comprising:

a magnetic head gimbal assembly that includes a magneto-resistive effect device;

a magnetic head that includes the magneto-resistive effect device, mounted on the magnetic head gimbal assembly; and

a magnetic recording medium that reproduces information using the magnetic head, wherein

the magneto-resistive effect device includes

a stacked body stacked on a substrate, the stacked body including;

a first magnetic layer that includes one or more metals selected from the group consisting of iron, cobalt, and nickel,

a second magnetic layer stacked on the first magnetic layer, having a composition that is different from the first magnetic layer, and

a spacer layer disposed between the first magnetic layer and the second magnetic layer;

a pair of first electrodes that feeds current to the stacked body;

a strain introduction member that applies strain to the stacked body, that is provided near the stacked body, and by applying strain to the stacked body, biases magnetization directions of the first magnetic layer and the second magnetic layer in different directions; and

a second electrode that applies a voltage to the strain introduction member, wherein

the magnetization directions of the first magnetic layer and the second magnetic layer are changed by the application of an external magnetic field, and

the external magnetic field is detected by a change in resistance between the first electrodes due to the change in the magnetization directions.