Amador, S.Pershan, PeterStragier, H.Swanson, B. D.Tweet, D. J.Sorensen, L. B.Sirota, E. B.Ice, G. E.Habenschuss, A.2013-03-011989Amador, S., Peter S. Pershan, H. Stragier, B. D. Swanson, D. J. Tweet, L. B. Sorensen, E. B. Sirota, G. E. Ice, and A. Habenschuss. 1989. Synchrotron studies of the first-order melting transitions of hexatic monolayers and multilayers in freely suspended liquid-crystal films. Physical Review A 39(5): 2703-2708.1050-29471094-1622http://nrs.harvard.edu/urn-3:HUL.InstRepos:10357467Synchrotron x-ray diffraction has been used to study the surface and the interior hexatic-to-liquid (smectic-I to smectic-C) melting transitions of freely suspended liquid-crystal films of N-[4'-(n-heptyl)benzylidene]-4-(n-heptyl)aniline (7O.7) five molecular layers thick. Both the surface hexatic monolayers and the interior hexatic layers melt via hysteretic first-order transitions. After the two surface layers undergo a first-order transition to the smectic-I phase, the surface hexatic correlation length \(\xi\) evolves smoothly from \(\sim 100 to \sim 300 \mathring{A}\) with a roughly square-root form, \(\xi \sim \mid T-T_c \mid ^{1/2}\).en-USJournal Article2013-03-0110.1103/PhysRevA.39.2703