Dequidt A, Oswald P
Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon Cedex 07, France.
Eur Phys J E Soft Matter. 2006 Apr;19(4):489-500. doi: 10.1140/epje/i2006-10004-6. Epub 2006 Apr 13.
We studied the formation of chi disclination lines in planar cholesteric samples placed in a temperature gradient near the cholesteric to smectic A phase transition. We observed that the first simple line which forms close to the smectic-cholesteric front zigzags when it is perpendicular to the direction of planar anchoring and is straight for other orientations. This instability is similar to Herring instability for crystalline surfaces. We show numerically that it originates from a strong increase of the elastic anisotropy close to the transition. In addition, we propose a new method to measure the pitch divergence at the smectic to cholesteric phase transition.
我们研究了置于接近胆甾相到近晶A相转变温度梯度中的平面胆甾相样品中手征性向错线的形成。我们观察到，在近晶 - 胆甾相前沿附近形成的第一条简单线，当它垂直于平面锚定方向时呈锯齿状，而在其他取向时是直的。这种不稳定性类似于晶体表面的赫林不稳定性。我们通过数值计算表明，它源于接近转变时弹性各向异性的强烈增加。此外，我们提出了一种新方法来测量近晶相到胆甾相转变时的螺距发散。
