Spatially resolved x-ray studies of liquid crystals with strongly developed bond-orientational order

TL;DR

This study uses x-ray techniques to analyze the spatial inhomogeneities and high-order bond-orientational order in liquid crystal films, revealing detailed phase transition behaviors and validating multicritical scaling theory.

Contribution

It provides the first direct measurement of up to 25 bond-orientational order parameters in liquid crystal hexatic phases using angular x-ray cross-correlation analysis.

Findings

Identification of spatial inhomogeneities near phase transition

Observation of large hexatic domains at lower temperatures

Validation of multicritical scaling theory with higher order corrections

Abstract

We present an x-ray study of freely suspended hexatic films of the liquid crystal 3(10)OBC. Our results reveal spatial inhomogeneities of the bond-orientational (BO) order in the vicinity of the hexatic-smectic phase transition and the formation of large scale hexatic domains at lower temperatures. Deep in the hexatic phase up to 25 successive sixfold BO order parameters have been directly determined by means of angular x-ray cross-correlation analysis (XCCA). Such strongly developed hexatic order allowed us to determine higher order correction terms in the scaling relation predicted by the multicritical scaling theory over a full temperature range of the hexatic phase existence.