Zuhail K P, Sathyanarayana P, Seč D, Čopar S, Škarabot M, Muševič I, Dhara S
School of Physics, University of Hyderabad, Hyderabad-500046, India.
J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Mar;91(3):030501. doi: 10.1103/PhysRevE.91.030501. Epub 2015 Mar 10.
We observe that topological defects in nematic colloids are strongly influenced by the elasticity and onset of smectic layering across the nematic (N) to smectic-A (SmA) phase transition. When approaching the SmA phase from above, the nematic hyperbolic hedgehog defect that accompanies a spherical colloidal inclusion is transformed into a focal conic line in the SmA phase. This phase transformation has a strong influence on the pairwise colloidal interaction and is responsible for a structural transition of two-dimensional colloidal crystals. The pretransitional behavior of the point defect is supported by Landau-de Gennes Q-tensor modeling accounting for the increasing elastic anisotropy.
我们观察到，向列型胶体中的拓扑缺陷受到向列相（N）到近晶A相（SmA）相变过程中弹性和近晶层状结构起始的强烈影响。当从上方接近SmA相时，伴随球形胶体包裹体的向列型双曲刺猬缺陷在SmA相中转变为焦锥线。这种相变对胶体间的成对相互作用有很大影响，并导致二维胶体晶体的结构转变。点缺陷的预转变行为得到了考虑弹性各向异性增加的朗道-德热纳Q张量模型的支持。
