题名 |
Several Anomalous Thermal Behaviors in Free-Standing N-(4-n-butoxybenzylidene)-4-n-octylaniline Films |
作者 |
P. J. Wu;Y. C. Shen;Y. H. Liu;C. R. Lo;A. J. Jin;C. C. Huang;C. Y. Chao |
关键词 | |
期刊名称 |
Chinese Journal of Physics |
卷期/出版年月 |
38卷3期(2000 / 06 / 01) |
页次 |
471 - 477 |
内容语文 |
英文 |
英文摘要 |
Entirely novel phenomena associated with the phase transitions of N-(4-nbutoxybenzylidene)-4-n-octylaniline (4O.8) free-standing liquid-crystal films are discovered. The hexatic-B ordering transition of the outermost surfaces has only a small thermal hysteresis and exhibits a predominant pretransitional heat-capacity anomaly, in disagreement with the predictions of two-dimensional melting theory. In light of our recently established results of the surface-enhanced two-stage freezing transformation, even a single interior layer shows a smectic-A-crystal-B transition and exhibits a drastic thermal hysteresis (about 10℃). The melting transitions are also unique in which, even though the interior crystal-B phase can unusually melt at a much higher temperature than the surfaces, the surface anomaly peaks occur in a layer-by-layer fashion with about the same sizes as in the cooling. |
主题分类 |
基礎與應用科學 >
物理 |
被引用次数 |