Method and system for the individualized characterization of magnetic elements based on ferromagnetic resonance.

• US 20070187513A1
• Filed: 02/14/2007
• Published: 08/16/2007
• Est. Priority Date: 02/14/2006
• Status: Active Grant

• Current Assignee: Micromag 2000, S.L.
• Original Assignee: Micromag 2000, S.L.
• Inventors: Hernando Grande, Antonio, Marin Palacios, Pilar, Calvo Robledo, Javier, Cortina Blanco, Daniel Blanco
• Granted Patent: US 7,898,251 B2
• Time in Patent Office: Days
• US Class Current: 235/462.370
• CPC Class Codes: G01N 24/10 by using electron paramagnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 33/14 Measuring or plotting hysteresis curves G01R33/1207 takes precedence
• CPC Class Codes: G01R 33/60 using electron paramagnetic resonance G01R33/24, G01R33/62 take precedence
• CPC Class Codes: H01F 1/15391 Elongated structures, e.g. wires

Abstract

In a method and system for the characterization of a magnetic element based on ferromagnetic resonance, the magnetic element presents ferromagnetic resonance and its own characteristic resonance frequency. The system includes: mechanism for application of a low-frequency electromagnetic field in a given area; a mechanism for application of a high-frequency electromagnetic wave the same as the characteristic resonance frequency of the magnetic element in said same Area; and a control unit configured so as to control the simultaneous application of the low-frequency electromagnetic field so that in response to the introduction of the magnetic element in the area the magnetic element absorbs the high-frequency electromagnetic wave with a frequency the same as that of the low-frequency electromagnetic field, so the wave is modulated. The system also comprises: a mechanism for reception of this unique individual modulated wave characteristic of each element, and a mechanism for assignment of the unique modulated wave to the element.

Claims

1. Method for the individualized characterization of a magnetic element (12) based on ferromagnetic resonance, in which said magnetic element exhibits the property of ferromagnetic resonance and a resonance frequency of its own, said method comprising the following steps:

application in a given area of a low-frequency electromagnetic field,

simultaneous application in the same area of a electromagnetic wave of a high frequency the same as the characteristic resonance frequency of the magnetic element,

insertion of the magnetic element in said given area, with the result that it absorbs the high-frequency electromagnetic wave with a frequency the same as that of the low-frequency electromagnetic field, so said wave is modulated,

reception of this unique and individual modulated wave characteristic of each magnetic element, and

assignment of said unique modulated wave to the magnetic element.

2. Method according to claim 1, where assignment of said unique individual modulated wave characteristic of each magnetic element includes modifying said modulated wave.

3. Method according to claim 1, in which said magnetic element is characterized by a low-frequency hysteresis loop.

4. Method according to claim 1, characterized in that said magnetic element is an amorphous magnetic element.

5. Method according to claim 1, characterized in that said magnetic element is a magnetic microwire

6. Method according to claim 1, characterized in that said low frequency lies between 50-800 Hz.

7. Method according to claim 1, characterized in that said high frequency lies between 0.5-20 GHz.

8. Use of a method of individualized characterization of a magnetic element according to claim 1 for identification of said magnetic element, characterized in that it comprises:

carrying out an initial characterization on a first magnetic element, thereby obtaining a first unique modulated signal by applying said method of characterization,

applying said method of characterization to a second magnetic element and obtaining a second unique modulated wave

comparing said first and second modulated waves and, if they are the same, identifying said second magnetic element as said first magnetic element.

9. System for the characterization of a magnetic element (12) based on ferromagnetic resonance, said magnetic element (12) presenting the property of ferromagnetic resonance and a characteristic resonance frequency;

the system comprises;

means of application of a low-frequency electromagnetic field (20) in a given area.

means of application of a high-frequency electromagnetic wave (40) the same as the characteristic resonance frequency of the magnetic element in that same given area.

means of control (10) configured so as to control the simultaneous application of said low-frequency electromagnetic field and said high-frequency electromagnetic wave, such that in response to the introduction of the magnetic element in said given area, the magnetic element absorbs the high-frequency electromagnetic wave with a frequency the same as that of the low-frequency electromagnetic field, so said wave is modulated;

the system also comprises;

means of reception (61) of this unique and individual modulated wave characteristic of each magnetic element, and

means of assignment (60, 70 10) of said unique modulated wave to the magnetic element.

10. System according to claim 9, where said means for assignment of said unique individual modulated wave characteristic of each magnetic element to said magnetic element includes means of encoding said modulated wave.

11. System according to claim 9, in which said magnetic element is characterized by a low-frequency hysteresis loop.

12. System according to claim 9, characterized in that said magnetic element is an amorphous magnetic element.

13. System according to claim 9, characterized in that said magnetic element is a magnetic microwire.

14. System according to claim 9, characterized in that said low frequency is between 50-800 Hz.

15. System according to claim 9, characterized in that said high frequency lies between 0.5-20 GHz.

16. Use of a system of individualized characterization of a magnetic element according to claim 9 for identification of said magnetic element, characterized in that it comprises:

carrying out an initial characterization on a first magnetic element, thereby obtaining a first unique modulated signal by applying said system,

applying said system of characterization to obtain a second unique modulated wave of a second magnetic element, and

comparing said first and second modulated waves and, if they are the same, identifying said second magnetic element as said first magnetic element.