Analysis Of Magnetic Properties Of Amorphous Thin Films Used In Magnetic Field Sensor

Compared with other magnetic field sensors, the giant magneto impedance(GMI) magnetic field sensor, which is made of an amorphous film, has the advantages of high sensitivity, rapid response, and so on. Morphous thin film is a kind of special amorphous alloy. The existing data indicate that the amorphous film's magnetic properties including the AC impedance, electrical conductivity, magnetic permeability, and so on are different under different external static conditions. The magnetic properties of amorphous thin films are closely related to the microstructure of its microstructure. Therefore, it is significant to study the magnetization structure of amorphous thin films under different external conditions.This topic selected Co amorphous films used in GMI sensor as the research object, and simulation the static magnetic field working environment of amorphous film in the sensor. Then simulating its internal magnetization vector distribution in the conditions of circular and longitudinal static field. Firstly, this paper will elaborate magnetic calculation methods and principles. Two numerical methods are selected for solving. The first finite element method: Simulating the stable state magnetization vector M distribution of amorphous thin films under the condition of annular static field. Comparating and analysing of the magnetization vector M distribution under the different size and direction of the ring static field condition is carried out. Then studying on the properties of the ring magnetization of amorphous thin films. On the other hand, using the second finite difference method, and simulating Co amorphous thin film magnetization evolution process in the another working environment that is longitudinal static field with external coils. To improve the simulation speed and precision, using the software MATLAB to carry out the selective dimension of amorphous thin films' magnetic domain structure. Based on the principle of minimum energy, simplificating the formula and simulating the distribution of the single magnetization vector m of the each section of the amorphous film. On the basis of above, Comparating and analysing of the magnetization vector m distribution under the different size and direction of the rectilinear direction static field condition is carried out. Then studying on the properties of the rectilinear direction magnetization of amorphous thin films.