双轴向列相Fréedericksz转变的Monte Carlo模拟

Monte Carlo Simulation of Fréedericksz Transitions in Biaxial Nematic Liquid Crystals

通过Monte Carlo方法研究了在磁场诱导下的双轴向列相液晶的Fréedericksz转变,在模拟的过程中采用了London色散力近似。考虑3种不同的排列方式,通过改变3个分子轴的磁化率和磁场方向,讨论了9种不同的Fréedericksz转变并分别给出了相应的阈值磁场,通过计算机的模拟实现了短轴u和v的转变,长轴w和短轴u的转变以及长轴w和短轴v的转变。模拟结果表明,在给定假设的情况下满足单一弹性常数近似。研究结果对发展双轴液晶显示器件有一定的理论指导意义。

With Monte Carlo simulation,this paper investigated Fréedericksz transitions of biaxial nematics induced by an external magnetic field.In the simulation process,the pair potential in London＇s dispersion forces approximation was used.With three different orientations,nine different Fréedericksz transitions were discussed by changing the molecular magnetic susceptibility and the directions of magnetic field.The transition of two short axes u and v,the transition of long axis w and short axis u,and the transition of long axis w and short axis v were all simulated.With the result of simulations,relations of the nine elastic constants can be discussed and they are fit with one elastic constant approximation.The result is practical in the sense that it works as a theoretical basis for developing biaxial display device.