Physical Review E
focal conic domains, saddle-splay, phase, transition, evolution, constants, curvature, layer
Hybrid aligned nematic films placed onto an isotropic fluid substrate exhibit an unusual periodic stripe domain structure that appears only when the thickness of the film is smaller than a few tenths of a micrometer. We investigated the effect of a magnetic field on the threshold between the periodic stripe domains and the aperiodic deformed structure of the director. As experimentally observed, a magnetic field applied along the stripe domains favors a nonperiodic state with the director undistorted in the horizontal plane. The experimental findings are confirmed by a theory that takes into account not only the usual type of the elastic distortions, but also the so-called saddle-splay elasticity. A comparison of the experimental and theoretical data allows one to estimate that the saddle-splay elastic constant K24 is of the same order of magnitude as the bulk elastic constants; this result agrees with independent studies of confined liquid crystal systems.
Sparavigna, A.; Lavrentovich, Oleg; and Strigazzi, A. (1995). Magnetic-Field Effect on Periodic Stripe Domains in Nematic Liquid-Crystals. Physical Review E 51(1), 792-795. doi: 10.1103/PhysRevE.51.792 Retrieved from http://digitalcommons.kent.edu/cpippubs/197