Sirota, E. B.Pershan, PeterSorensen, L. B.Collett, J.2013-03-011985Sirota, E. B., Peter S. Pershan, L. B. Sorensen, and J. Collett. 1985. X-ray studies of tilted hexatic phases in thin liquid-crystal films. Physical Review Letter 55(19): 2039–2042.0031-90071079-7114http://nrs.harvard.edu/urn-3:HUL.InstRepos:10357489X-ray-diffraction studies of the structures and phase transitions of the tilted hexatic phases (smectic F and smectic I) in thin liquid-crystal films of 4-n-heptyloxybenzylidene-4-n-heptylaniline (70.7) are reported. The measured correlation lengths were strongly anisotropic in both phases. The smectic-I to smectic-F transition is first order as expected from the symmetry change. The smectic-F to smectic-G transition is first order with strong pretransition effects and becomes nearly second order as the film thickness is decreased.en-USJournal Article2013-03-0110.1103/PhysRevLett.55.2039