Multiple-step melting in two-dimensional hexatic liquid-crystal films

被引:62
作者
Chou, CF [1 ]
Jin, AJ
Hui, SW
Huang, CC
Ho, JT
机构
[1] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA
[2] Appl Mat Inc, Santa Clara, CA 95054 USA
[3] Roswell Pk Canc Inst, Dept Biophys, Buffalo, NY 14263 USA
[4] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA
[5] SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA
关键词
D O I
10.1126/science.280.5368.1424
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
An unexpected three-stage melting transition has been observed in two-dimensional (2D) free-standing liquid-crystal films by in situ electron-diffraction and optical-reflectivity measurements. These data suggest the existence of two phases between the 2D solid and liquid: a hexatic phase and, at a higher temperature, an intermediate liquid phase with hexatic-like positional correlations (similar to 40 angstroms) but no long-range orientational order. Previous high-resolution heat-capacity measurements have revealed a divergent-like anomaly at the hexatic-liquid transition that sharply contradicts the predictions of 2D melting theories. The observation of an intermediate isotropic phase may alter our understanding of 2D melting and lead to reconciliation between current experiments and theories.
引用
收藏
页码:1424 / 1426
页数:3
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