Twist disclination loops in a bent-core nematic liquid crystal†

摘要: We report on the generation and stability of half-strength twist disclination loops separating planar π-twisted regions in a bent-core nematic liquid crystal with anchoring. Loops L(P) L(T) surrounding domains, respectively, are both generated during relaxation from quasi-homeotropic splay-Freedericksz state. demonstrate that metastable twisted state occurs as rule region lateral separation singular formed via wall pincement collapsing at different rates. The results provide first experimental confirmation early theoretical prediction that, for circular L(P), there exists critical radius Rc regimes growth decay. varies temperature indicating its dependence elastic anisotropy. R, which changes quasistatically around Rc, is linear time long thread regime L(T). An earlier model extended to fully account observed dynamics subcritical supercritical loops, also extract related viscoelastic parameter.