Shalaginov A N, Sullivan D E
Department of Physics and Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Mar;65(3 Pt 1):031715. doi: 10.1103/PhysRevE.65.031715. Epub 2002 Mar 1.
Static and dynamic phenomena in overheated free-standing smectic-A films are studied theoretically. The work is based on a generalization, introduced recently by the authors, of de Gennes' theory for a confined presmectic liquid. In this approach, smectic ordering in an overheated film is caused by an intrinsic surface contribution to the film free energy and vanishes at some temperature depending on the number of layers. Here the theory is further generalized to study the dynamics of films with planar inhomogeneities. A static application is to determine the profile of the film meniscus and the meniscus contact angle, the results being compared with those of a recent study employing de Gennes' original theory. The dynamical generalization of the theory is based on a time-dependent Ginzburg-Landau approach. This is used to compare two modes for layer-thinning transitions in overheated free-standing films, namely, "uniform thinning" versus nucleation of dislocation loops. It is concluded that the nucleation mechanism dominates provided there is a sufficiently large pressure difference arising from meniscus curvature. Properties such as the line tension and velocity of a moving dislocation line are evaluated self-consistently by the theory.
对过热的独立近晶A膜中的静态和动态现象进行了理论研究。这项工作基于作者最近对德热纳关于受限预近晶液体理论的推广。在这种方法中，过热膜中的近晶有序是由膜自由能的固有表面贡献引起的，并在某个取决于层数的温度下消失。在此，该理论进一步推广以研究具有平面不均匀性的膜的动力学。一个静态应用是确定膜弯月面的轮廓和弯月面接触角，并将结果与最近一项采用德热纳原始理论的研究结果进行比较。该理论的动态推广基于随时间变化的金兹堡 - 朗道方法。这用于比较过热独立膜中层变薄转变的两种模式，即“均匀变薄”与位错环的成核。得出的结论是，只要弯月面曲率产生足够大的压力差，成核机制就占主导。该理论自洽地评估了诸如移动位错线的线张力和速度等性质。
