水基磁性液体的场诱导光衍射特性的研究

设计了一套用于研究磁性液体的场诱导静态和动态光衍射特性的实验装置.通过在样品的后方放置一个适当孔径的光阑,实现了定量研究其衍射特性的目的.采用沿衍射方向移动光阑的方法定量地研究了衍射光的空间分布.设计了一个指数衰减函数用来拟合动态衍射实验的数据,获得动态衍射的特征时间.以两种不同浓度的表面包覆型水基氧化铁磁性液体样品为例,定量地实验研究了其场诱导光衍射特性与外磁场强度和样品浓度的关系.结果表明,磁性液体的场诱导结构对光的静态和动态衍射与外磁场的强度和磁性液体的浓度有关.其静态衍射与外磁场强度呈非单调的关系;其动态衍射的特征时间与外磁场的强度成反比,与磁性液体的浓度成正比.对实验中观察到的场诱导静态和动态衍射特性的物理机理进行了详细的分析.

Magnetic-field-induced Diffraction Properties of Light by Water-based Magnetic Liquids

An experimental setup is designed to investigate the field-induced static and dynamic diffraction properties.The corresponding diffraction properties are investigated quantitatively by putting a diaphragm with an appropriate aperture behind the sample.By moving aperture along diffraction to study quantitatively the spatial distribution of light diffraction.An exponentially decaying function is applied to fit the experimental data of the dynamic diffraction,and the corresponding characteristic time is obtained.The dependence of the field-induced diffraction properties on the magnetic field strength and the sample concentration is investigated.The static and dynamic light diffraction of the field induced magnetic liquid structure depends on magnetic field intensity and the concentration of magnetic fluid.The relationship between diffraction and external static magnetic field strength is non-monotonic.The dynamic diffraction's characteristic time is inversely proportional to the intensity of external magnetic field and directly proportional to the concentration of magnetic fluid.