Physical Review E
We develop a lattice model for the splay flexoelectric effect in nematic liquid crystals. In this model, each lattice site has a spin representing the local molecular orientation, and the interaction between neighboring spins represents pear-shaped molecules with shape polarity. We perform Monte Carlo simulations and mean-field calculations to find the behavior as a function of interaction parameters, temperature, and applied electric field. The resulting phase diagram has three phases: isotropic, nematic, and polar. In the nematic phase, there is a large splay flexoelectric effect, which diverges as the system approaches the transition to the polar phase. These results show that flexoelectricity can be a statistical phenomenon associated with the onset of polar order.
Dhakal, Subas and Selinger, Jonathan (2010). Statistical Mechanics of Splay Flexoelectricity in Nematic Liquid Crystals. Physical Review E 81(3). doi: 0.1103/PhysRevE.81.031704 Retrieved from http://digitalcommons.kent.edu/cpippubs/103