Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Materials Science and Engineering

X-ray diffraction

Lawrence University Honors Projects

Articles 1 - 1 of 1

Full-Text Articles in Physics

Temperature Dependent Surface Reconstruction Of Freely Suspended Films Of 4-N-Heptyloxybenzylidene-4-N-Heptylaniline, Daniel E. Martinez Zambrano Jun 2015

Temperature Dependent Surface Reconstruction Of Freely Suspended Films Of 4-N-Heptyloxybenzylidene-4-N-Heptylaniline, Daniel E. Martinez Zambrano

Lawrence University Honors Projects

Surfaces of freely suspended thick films of 4-n-heptyloxybenzylidene-4-n-heptylaniline (7O.7) in the crystalline-B phase have been imaged using non-contact mode atomic force microscopy. Steps are observed on the surface of the film with a height of 3.0 +/- 0.1 nm corresponding to the upright molecular length of 7O.7. In addition, we find that the step width varies with temperature between 56 and 59 degrees C. The steps are many times wider than the molecular length, suggesting that the steps are not on the surface but instead originate from edge dislocations in the interior. Using a strain model for liquid crystalline layers …