Two-dimensional melting of an anisotropic crystal observed at the molecular level

被引：52

作者：

Sikes, HD ^{[1
]}

Schwartz, DK ^{[1
]}

机构：

[1] TULANE UNIV,DEPT CHEM,NEW ORLEANS,LA 70118

来源：

SCIENCE | 1997年 / 278卷 / 5343期

关键词：

D O I：

10.1126/science.278.5343.1604

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：

A distinctive two-dimensional (2D) melting transition occurring at nearly 100 degrees Celsius (degrees C) has been observed in Langmuir-Blodgett films by in situ atomic force microscopy (AFM). A 2D orthorhombic crystal phase melted to a 2D smectic phase at about 91 degrees C. The smectic phase was characterized by 1D molecular periodicity with short-range correlations (about 40 angstroms). At 95 degrees C, the smectic order melted! to form a hexatic phase. infrared spectroscopy measurements were consistent with the AFM observations. These observations support the dislocation-mediated melting scenario for an anisotropic 2D crystal predicted by Ostlund and Halperin. A longer wavelength height modulation was also observed in the smectic and hexatic phases.

引用

页码：1604 / 1607

页数：4

共 27 条

[1] TEMPERATURE-DEPENDENT ELECTRON-DIFFRACTION STUDIES OF CADMIUM ARACHIDATE MONOLAYERS AND MULTILAYERS [J].