Magnetic field sensor utilizing ferromagnetic nanometer ring strong magnetic resistance effect

Abstract

The invention provides a magnetic field sensor utilizing the giant magnetoresistive effect of a ferromagnetic nano-ring, and belongs to the technical field of magnetic nano-sensors. The sensor is composed of a ferromagnetic nano-ring prepared on a substrate of nanometer size and a group of lead wires; the group of lead wires connected to the two ends of the ring also serve as a constant current source connecting wire and a voltage measurement connecting wire; the outside diameter D of the ferromagnetic nano-ring is 7 nm-10 um; the inside diameter d is smaller than the outside diameter D; the width of the ring is 5 nm-1 um; and the thickness of the nano-ring is 1 nm-500 nm. The sensor utilizes the ferromagnetic nano-ring under the action of the outside magnetic field, and the resistance the ferromagnetic nano-ring changes greatly, so as to detect the change of the outside magnetic field; the manufacture is very simple; the output signal is large; and the response is fast. The sensor is especially applicable to the detection of the threshold value of the magnetic field change; besides, the magnetic field sensitivity of the magnetic field transformation point can reach 2-10 percent/Oe or is higher than 2-10 percent/Oe, and the sensor also can serve as a magnetic cell.

Description

technical field [0001] The invention belongs to the technical field of magnetic nanometer sensors, in particular to a magnetic field detection sensor using a ferromagnetic nanoring structure material. Background technique [0002] Magnetic field detection is one of the important aspects of magnetic measurement, and it has a wide range of applications in the national economy, such as the magnetic recording readout head in the information industry, the measurement of the geomagnetic azimuth in navigation, the measurement of the magnetic field azimuth on the aircraft, and the size of the geomagnetic field in oil exploration. and orientation measurement, measurement of magnetic flux leakage and remanence in industrial production, non-destructive testing of product quality in metallurgy and aviation industry, application of weak magnetic anti-counterfeiting technology, etc., the existing technology mainly uses anisotropic magnetoresistance materials, Such as NiFe, NiCo and other ...

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Problems solved by technology

[0003] At present, the widely used magnetic sensors include anisotropic magnetoresistance sensor, spin valve giant magnetoresistance sensor, magnetic tunnel junction giant magnetoresistance sensor, etc. Anisotropic magnetoresistance sensor has small output signal and high noise due to the small magnetoresistance of the material. Large; the magnetic field sensitivity of the spin valve giant magnetoresistance sensor is significantly improved compared with the anisotropic magnetoresistance sensor, which can reach 1% / Oe, but the total magnetoresistance change is only 2-5%, and the output signal amplitude is not large; Compared with the previous two sensors, the magnetic tunnel junction giant magnetoresistance sensor requires higher preparation technology, and needs to prepare an ultra-thin and uniform insulating layer of 1 nanometer, and it is difficult to ensure its consistency in mass production.

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