High-resolution X-ray scattering studies of the nonpolar thermotropic liquid crystal 4-n-pentylphenylthiol-4'-n-octyloxybenzoate (\bar{8}S5) in aerosil gel nano-networks reveal that the aerosil-induced disorder significantly alters both the nematic to Smectic-A and Smectic-A to Smectic-C phase transitions. The limiting Smectic-A correlation length follows a power-law dependence on the aerosil density in quantitative agreement with the limiting lengths measured previously in other Smectic-A liquid crystal gels. The Smectic-A to Smectic-C liquid crystalline phase transition is altered fundamentally by the presence of the aerosil gel. The onset of the Smectic-C phase remains relatively sharp but there is an extended coexistence region where Smectic-A and Smectic-C domains can exist.
@article{arxiv.1104.5670,
title = {Smectic-A and Smectic-C Phases and Phase Transitions in Liquid Crystal-Aerosil Gels},
author = {B. Freelon and M. Ramazanoglu and P. J. Chung and P. Valdivia and C. W. Garland and R. J. Birgeneau},
journal= {arXiv preprint arXiv:1104.5670},
year = {2015}
}