The Study of Magneto-optical Effect in Paramagnetic Media under Pulsed High Magnetic Field

The Study of Magneto-optical Effect in Paramagnetic Media under Pulsed High Magnetic Field
　　Magneto-optical effect results from the interaction of optical wave and magnetic moment. Faraday rotation is one of the most important magneto-optical effects that are applied widely. In this paper, magnetic properties, double-hump phenomena of the paramagnetic neodymium trifluoride ( NdF3 ) are studied theoretically and described in pulsed high magnetic neodymium magnets field and at low temperature.Dai Imaizumi et al. systematically studied magnetic and magneto-optical properties of the terbium metaborate glass ( 25Tb2O3 -75B2O3) modified with Mn2+ ions in pulsed magnetic field and at low temperature.
　　They discovered the enhancement of the Faraday rotation effect in pulsed magnetic field and at low temperature. In this paper, we theoretically calculated the magnetic properties of the paramagnetic magneto-optic media with quantum theory in pulsed high magnetic field and at low temperature. It is indicated that the Faraday Rotation in paramagnetic magneto-optical media has the obvious double-hump phenomena when the thermal energy k BT approaches the effective field energyμ0μBHi(μ0μBHe). Besides, the Faraday effects, especially under an extremely high pulsed field, are found to neodymium magnets depend essentially on the effective field H i( H e). Our results are shown that the enhancements of the Faraday Rotation can be obtained under high pulsed field and low temperature. It is also shown that the much larger Faraday Rotation can be reached under an extremely high pulsed field in weak magnetic media.
　　The theory is in good agreement with experimental results.In addition, it has been theoretically proved that there are much larger Faraday magneto-optical effect in ferromagnetic and ferrimagnetic magnetic-optical materials, but Faraday rotation of paramagnetic media are not well understood in low magnetic field so far. In this work, Faraday magneto-optic effects of the paramagnetic media have been studied theoretically in extreme conditions. Some conclusions have been drawn: (1) Faraday rotation obviously presents much larger in pulsed high magnetic field and at low temperature. (2) Faraday rotation, especially under an extremely high magnetic field, were found to depend essentially on the effective field H i ( H e) rather than the magnetization M .Magneto-optical effect has widely applied to many fields such as magnet field measurement, information documentation and neodymium magnets etc. Theoretical research will help to realize the operation of magneto-optical effect. We will also introduce applied aero of the effect, such as the measurement of magnetic field and the magneto-optical storage.