Application
This sensor has the advantages of small size, low power consumption, high sensitivity, strong anti-interference ability, high reliability, and easy installation. It is used in the measurement of weak magnetic fields and based on weak magnetic fields. The geomagnetic navigation, digital smart compass, position measurement, counterfeit banknote identification, etc. have shown great advantages. It can also be used to make high-precision speed sensors, pressure sensors, angular displacement sensors, etc., which has broad application prospects. At present, foreign countries have Mass production of this type of permalloy integrated magnetoresistive sensor, and has a wide range of applications in industry, aerospace, navigation, medical instruments and other instruments.
Anisotropic magnetoresistance effect
The phenomenon that the resistance of a substance changes in a magnetic field is called the magnetoresistance effect. The magnetoresistance effect includes the ordinary magnetoresistance effect based on the Hall effect and various Anisotropy
Different magnetoresistance effects. For ferromagnetic metals (iron, cobalt, nickel and their alloys), when the applied magnetic field is parallel to the magnetization direction inside the magnet, the resistance hardly varies.
It changes with an external magnetic field; when the external magnetic field deviates from the inner magnetization direction of the metal, the resistance of the metal decreases, which is the anisotropic magnetoresistance effect. Permalloy
The resistivity of the film depends on the angle θ between the magnetization M and the direction of the current I, that is, ρ(θ) =ρ⊥+ (ρ∥-ρ⊥)cos2θ(1) p>
where ρ∥ and ρ⊥ are the resistivities parallel to M and perpendicular to M, respectively. Because permalloy (Fe20Ni80) has a large resistance change under a weak magnetic field, so
This is suitable for use under weak magnetic field conditions.