外场中半无限向列相液晶体系的相变

Phase Transition of Nematic Liquid Crystal in Semi-Infinite Sample in Outside Magnetic Field

考虑半无限向列相液晶体系在外加场和衬底非线性作用下的相变特征,包括远离衬底的液晶(体液晶)和表面的液晶的相变情况,得到三维体液晶和表面液晶的相变曲面.研究表明:体液晶的相变只和外磁场和温度有关系,而且发生相变的温度和外磁场是呈线性增大的;表面液晶的相变除了与外磁场和温度有关外,还与衬底和表面液晶的耦合强度,以及衬底的序参数有关系.

Taking into account the applied magnetic field and the substrate coupling strength in a semi-infinite sample to the phase character of bulk liquid crystal and the surface,a phase diagram of the three dimension bulk liquid crystal and surface liquid crystal are obtained.It is the conclusion after research： the phase transition of the bulk only relates to the magnetic field and temperature,and the phase transition temperature linear increases with the magnetic field.The phase transition of the surface liquid crystal relates to not only the magnetic field and temperature,but also the coupling strength of the surface liquid crystal and substrate order parameter.