相关论文: Spatially resolved x-ray studies of liquid crystal…
We report on X-ray studies of freely suspended hexatic films of three different liquid crystal compounds. By applying angular X-ray cross-correlation analysis (XCCA) to the measured diffraction patterns the parameters of the…
We present an x-ray study of liquid crystal membranes in the vicinity of hexatic-smectic phase transition by means of angular x-ray cross-correlation analysis (XCCA). By applying two-point angular intensity cross-correlation functions to…
An x-ray scattering approach to determine the two-dimensional (2D) pair distribution function (PDF) in partially ordered 2D systems is proposed. We derive relations between the structure factor and PDF that enable quantitative studies of…
Using a high resolution Monte Carlo simulation technique based on multi-histogram method and cluster-algorithm, we have investigated critical properties of a coupled XY model, consists of a six-fold symmetric hexatic and a three-fold…
Experimental and theoretical studies of a smectic-hexatic transition in freely suspended films of 54COOBC compound are presented. X-ray investigations revealed a discontinuous first-order transition into the hexatic phase. Moreover, the…
X-ray diffraction studies of the bond-orientational order in the hexatic-B phase of 75OBC and 3(10)OBC compounds are presented. The temperature evolution of an angular profile of a single diffraction peak is analyzed. Close to the…
The hexatic phase predicted by the theories of two-dimensional melting is characterised by the power law decay of the orientational correlations whereas the in-layer bond orientational order in all the hexatic smectic phases observed so far…
We report results from X-ray scattering studies of the angular structure factor of liquid crystal hexatic-B films. According to the sixfold rotational symmetry of the hexatic-B phase, its characteristic scattering splits into six…
Addressing the nature of an unexpected smectic-A' phase in liquid crystal 54COOBC films, we perform large scale Monte Carlo simulations of a coupled hexatic-nematic XY model. The resulting finite-temperature phase diagram reveals a small…
We propose that extended orientational correlations can appear at the surface of supercooled heavy noble liquid metals, due to the same compressive forces that cause reconstruction of their crystal surfaces. Simulations for liquid Au show a…
Comprehensive x-ray scattering studies have characterized the smectic ordering of octylcyanobiphenyl (8CB) confined in the hydrogen-bonded silica gels formed by aerosil dispersions. For all densities of aerosil and all measurement…
We report a high-resolution x-ray scattering study of the smectic liquid crystal octylcyanobiphenyl (8CB) confined to aligned colloidal aerosil gels. The aligned gels introduce orientational fields that promote long-range nematic order…
We study the kinetics of the nematic-isotropic transition in a two-dimensional liquid crystal by using a lattice Boltzmann scheme that couples the tensor order parameter and the flow consistently. Unlike in previous studies, we find the…
High energy x-ray diffraction is used to investigate the bulk oxygen ordering properties of YBa_2Cu_3O_{6+x}. Superstructures of Cu-O chains aligned along the b axis and ordered with periodicity ma, along the a axis have been observed. For…
Simple symmetry considerations would suggest that the transition from the smectic-A phase to the long-range bond orientationally ordered hexatic smectic-B phase should belong to the XY universality class. However, a number of experimental…
The bent-core liquid crystals (LCs) are highly regarded as the next-generation materials for electro-optic devices. The nematic (N) phase of these LCs possesses highly ordered smectic-like cybotactic clusters which are promising in terms of…
We have used an extended Scaled-Particle Theory that incorporates four-body correlations through the fourth-order virial coefficient to analyse the orientational properties of a fluid of hard right-angle triangles. This fluid has been…
I describe new phases of a chiral liquid crystal with nematic and hexatic order. I find a conical phase, similar to that of a cholesteric in an applied magnetic field for Frank elastic constants $K_2>K_3$. I discuss the role of fluctuations…
The phase-ordering kinetics of a bulk uniaxial nematic liquid crystal is addressed using techniques that have been successfully applied to describe ordering in the O(n) model. The method involves constructing an appropriate mapping between…
The determination of phase behavior and, in particular, the nature of phase transitions in two-dimensional systems is often clouded by finite size effects and by access to the appropriate thermodynamic regime. We address these issues using…