Research On Transmittance Of Magnetic Liquid Film And Design Of Uniform Magnetic Field

Magnetic liquid has not only the liquidity of liquid, but also the magnetic properties of solid-stated magnetic materials. When the magnetic liquid film is thin enough, light can be through it. When the outside world has no magnetic field effects, magnetic particles in the magnetic liquid film will be in irregular order. When they are under the influence of the external magnetic field, the magnetic particles within a certain range of magnetic liquid will be arranged along the external magnetic field direction. At this point, the magnetic liquid will show its magneto-optic effect, such as double refraction effect, the Faraday effect, etc.It was verified about the influence of several variables to the magnetic fluid film optical transmittance by a series of experiments in this paper and the variables included the magnetic fluid film thickness, temperature, external magnetic field direction and the size of the external magnetic field. When external conditions remain the same and the light enters into three different thickness of magnetic fluid film, the relationship between the light transmittance and the magnetic liquid film thickness can be measured. External magnetic field generator is designed. The simulation helps to determine the size and direction of the external magnetic field and the uniformity of magnetic field intensity in the scope of placement of magnetic fluid film. Through several experiments, it is concluded that the changes in relationships between light transmittance and the magnetic field, and the changes in relationships between spectrometer scanning value and the magnetic field.By analysing the experimental data, it shows that when the magnetic fluid film magnetic field is vertical with the outside magnetic field, the light transmittance and spectrometer scanning value will increase with the increase of the external magnetic field; when the magnetic fluid film is in parallel with the outside magnetic field, light transmittance and spectrometer scanning value will both change smaller with the weakening of external magnetic field. According to the experimental results, the paper puts forward the theoretical feasibility of developing a new type of magnetic field sensor based on magnetic liquid.