液晶5CB磁化特性的数值分析

Numerical Analysis of Magnetic Properties of Liquid Crystal 5CB

以液晶5CB材料为研究对象,观察不同相(晶体相,向列相,各相同性相)下液晶5CB的磁化强度随外磁场变化情况,并进行数据处理分析,实验结果表明,外磁场强度在-5 000 A/m^5 000 A/m范围内变化时,液晶5CB表现出顺磁性,当外磁场强度值继续增加时,液晶5CB显示出抗磁性,对实验数据进行数值分析得出,在不同的外磁场强度范围内,不同相下液晶5CB磁化强度变化规律基本满足线性方程,当外磁场强度由临界值逐渐减小时,处于液晶相和各相同性相的液晶5CB出现不同程度的磁滞现象,考虑到液晶盒的锚定作用,得到液晶5CB在不同相下磁化规律的拟合直线方程,各有其特点,因此可以通过分析不同直线斜率和截距,从而判断出液晶5CB所处的不同状态.也可以根据液晶5CB的不同直线方程得出外磁场强度的变化范围.

Taking liquid crystal 5CB material as a study object, we observed the changing status of magnetization intensity of liquid crystal 5CB＇s with the external magnetic field at different phases （crystal, nematic and isotropic phase）.The results show that the liquid crystal 5CB shows paramagnetism when the magnetic field strength changes from -5 000 A/m to 5 000 A/m, but it exhibits anti-magnetism when the magnetic field strength increases continuously. According to numerical analysis for experimental data, the varying patterns of magnetization intensity of liquid crystal 5CB at different phases are basically show linear equation in different ranges of external magnetic-field strength. As external magnetic-field strength is declined gradually from critical value, the liquid crystal 5CB with liquid crystal phase or isotropic phase may present on magnetic hysteresis at different levels. Considering docking interactions of liquid crystal cell, the obtained fitting straight-line equation of magnetic pattern for liquid crystal 5CB has its own characteristics at various phases, so the state of liquid crystal 5CB can be judged by analyzing different straight slopes and intercepts, and the variation range of external magnetic-field strength can be gained based on different straight-line equations of liquid crystal 5CB.