MAGNETIC SENSOR AND MAGNETIC SENSOR APPARATUS

• US 20170209062A1
• Filed: 09/15/2016
• Published: 07/27/2017
• Est. Priority Date: 01/26/2016
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: SHIROTORI, Satoshi, KIKITSU, Akira, IWASAKI, Hitoshi
• Application Number:
  US15/266,352
• Publication Number:
  US 20170209062A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/0223 Magnetic field sensors
• CPC Class Codes: A61B 5/243 specially adapted for magnetocardiographic [MCG] signals
• CPC Class Codes: A61B 5/245 specially adapted for magnetoencephalographic [MEG] signals
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

A magnetic sensor according to an embodiment includes: a magneto-resistive film including a laminate structure, the laminate structure including a first magnetic layer, a second magnetic layer, and an intermediate layer arranged between the first magnetic layer and the second magnetic layer; and a pair of electrodes for supplying current in a first direction perpendicular to a laminate direction of the magneto-resistive film, wherein the second magnetic layer includes an amorphous magnetic layer, and a crystalline magnetic layer arranged between the amorphous magnetic layer and the intermediate layer, and a length of a current path of the magneto-resistive film is 10 μm or more.

Claims

1. A magnetic sensor comprising:

a magneto-resistive film including a laminate structure, the laminate structure including a first magnetic layer, a second magnetic layer, and an intermediate layer arranged between the first magnetic layer and the second magnetic layer; and

a pair of electrodes for supplying current in a first direction perpendicular to a laminate direction of the magneto-resistive film, wherein

the second magnetic layer includes an amorphous magnetic layer, and a crystalline magnetic layer arranged between the amorphous magnetic layer and the intermediate layer, and a length of a current path of the magneto-resistive film is 10 μ

m or more.

2. The sensor according to claim 1, wherein

the magneto-resistive film includes a plurality of magneto-resistive parts connected to each other in series, and each of the magneto-resistive parts includes the first magnetic layer, the intermediate layer, the crystalline magnetic layer, and the amorphous magnetic layer.

3. The sensor according to claim 1, wherein

the amorphous magnetic alloy layer has a thickness in the laminate direction of 10 nm or more.

4. The sensor according to claim 1, further comprising

a pair of magnetic films arranged at a side portion of the magneto-resistive film, wherein each of the magnetic films has a thickness in the laminate direction thicker than a thickness of each of the amorphous magnetic layer and the crystalline magnetic layer.

5. The sensor according to claim 1, wherein

the amorphous magnetic layer contains CoFeSiB or CoXY, wherein X represents at least one of Zr and Hf, and Y represents at least one of Ta and Nb.

6. The sensor according to claim 1, wherein

the crystalline magnetic layer is an alloy containing at least two elements of Co, Fe, and Ni.

7. A magnetic sensor apparatus comprising:

first and second magnetic sensors according to claim 1;

first and second resistors; and

a voltmeter, wherein the first magnetic sensor and the first resistor are connected to each other in series to configure a first serial portion, the second magnetic sensor and the second resistor are connected to each other in series to configure a second serial portion, the first serial portion and the second serial portion are connected to each other in parallel, and the voltmeter measures a potential difference between a connection node between the first magnetic sensor and the first resistor and a connection node between the second magnetic sensor and the second resistor.

8. The apparatus according to claim 7, wherein

the magneto-resistive film includes a plurality of magneto-resistive parts connected to each other in series, and each of the magneto-resistive parts includes the first magnetic layer, the intermediate layer, the crystalline magnetic layer, and the amorphous magnetic layer.

9. The apparatus according to claim 7, wherein

the amorphous magnetic alloy layer has a thickness in the laminate direction of 10 nm or more.

10. The apparatus according to claim 7, further comprising

a pair of magnetic films arranged at a side portion of the magneto-resistive film, wherein each of the magnetic films has a thickness in the laminate direction thicker than a thickness of each of the amorphous magnetic layer and the crystalline magnetic layer.

11. The apparatus according to claim 7, wherein

the amorphous magnetic layer contains CoFeSiB or CoXY, wherein X represents at least one of Zr and Hf, and Y represents at least one of Ta and Nb.

12. The apparatus according to claim 7, wherein

the crystalline magnetic layer is an alloy containing at least two elements of Co, Fe, and Ni.

13. A magnetic sensor apparatus comprising:

a magnetic sensor according to claim 1; and

a diagnosis apparatus including a processing analysis circuit for processing and analyzing a magnetic field detection signal from the magnetic sensor, and an imaging circuit for imaging an analysis result of the processing analysis circuit.

14. The apparatus according to claim 13, wherein

the magnetic sensor detects a magnetic field from a brain.

15. The apparatus according to claim 13, wherein

the magnetic sensor detects a magnetic field from a heart.

16. The apparatus according to claim 13, wherein

the magneto-resistive film includes a plurality of magneto-resistive parts connected to each other in series, and each of the magneto-resistive parts includes the first magnetic layer, the intermediate layer, the crystalline magnetic layer, and the amorphous magnetic layer.

17. The apparatus according to claim 13, wherein

the amorphous magnetic alloy layer has a thickness in the laminate direction of 10 nm or more.

18. The apparatus according to claim 13, further comprising

a pair of magnetic films arranged at a side portion of the magneto-resistive film, wherein each of the magnetic films has a thickness in the laminate direction thicker than a thickness of each of the amorphous magnetic layer and the crystalline magnetic layer.

19. The apparatus according to claim 13, wherein

the amorphous magnetic layer contains CoFeSiB or CoXY, wherein X represents at least one of Zr and Hf, and Y represents at least one of Ta and Nb.

20. The apparatus according to claim 13, wherein

the crystalline magnetic layer is an alloy containing at least two elements of Co, Fe, and Ni.