We observed undulated smectic textures for some compounds of the 4,n-alkyloxybenzoic (nOBAC) acid series, at transitions between the smectic and the isotropic phase and between the smectic and nematic phase. Studied compounds were 12OBAC, 16OBAC and a binary mixture of 12- and 16OBAC. The undulations are dressing a usual Schlieren texture. In the case of the binary mixture, an interesting fingerprint pattern is observed too.
@article{arxiv.0812.2178,
title = {Undulation textures at the phase transitions of some alkyloxybenzoic acids},
author = {A. Sparavigna and A. Mello and G. Massa},
journal= {arXiv preprint arXiv:0812.2178},
year = {2009}
}