Development of Scanning Tunneling Microscope Operated under High Pressure Environments

高压环境下扫描隧道显微镜的研制

基本信息

批准号：
09555101
负责人：
KAI Shoichi
金额：
$ 7.36万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

The aim of this research project is to develop a scanning tunneling microscope (STM) capable to be easily handled under super high pressure environments and to study on interfacial phase transition through STM observation of molecular alignments of liquid crystal monolayers as well as their alignment structures. The results obtained are following.(1) The improvement of a high pressure STM and the realization of its operation under 600 MPa were done.(2) The molecular alignments of CィイD260ィエD2 and CィイD270ィエD2 were directly observed with STM under 350MPa. Although phase transitions (PHs) of bulk phase of CィイD260ィエD2 and CィイD270ィエD2 were observed near 350MPa based on previous studies, PHs of the monolayers were not observed at least by 400MPa(3) The systematic observations were carried out for the molecular alignments of homologous series in monolayers of n-cyanobiphenyle (nCB) and n-alkyloxy-cyanobiphenle (nOCB) liquid crystals on highly oriented pyrolytic graphite (HOPG) and molybdenum d … More isulfide (MoSィイD22ィエD2) substrates using scanning tunneling microscope (STM), as well as two-phase mixtures of n-CB. In nCB with n=odd number, only the single row alignments in the monolayer was observed. The monolayer alignments of nCB with n=even on the other hand showed double row characteristics. For nOCB these tendencies were opposite, that is, single tow for n=even and double row for n=odd. Thus all the observed aspects clearly indicated the odd-even effect of carbon numbers in alkyl chains. The origin of the even-odd effect is due to the orientation of prana-zigzag planes of alkyl-chains in nCB and nOCB, which is perpendicular to the substrate plane. The odd-even effect is therefore strongly related to the strength of interactions with substrates through such an orientation. In nCB and nOCB for n=odd, the end carbon atom of an alkyl-chain must be free from and rigid substrates respectively. That is the interaction for n=even in nCB (nOCB) is stronger (weaker) than that for n=odd. This difference leads to basically two different alignments, I.e., the single and double rows. The proposed model has been verified by computer simulation Less

该研究项目的目的是开发能够在超高压环境下轻松处理的扫描隧道显微镜（STM），并通过对液体晶体单层及其比对结构的分子比对来研究界面相变。（1）改善高压STM的改善，并在600 MPa下实现其操作。（2）虽然在350MPA下直接观察到CII D260E D2和CII D2和CII D2270E D2的块状相位相变（pHS）。 Although phase transitions (PHs) of bulk phase of Cii D260E D2 and Cii D270E D2 were observed near 350MPa based on previous studies, PHs of the monolayers were not observed at least by 400MPa(3) The systematic observations were carried out for the molecular alignments of homologous series in monolayers of n-cyanobiphenyle (nCB) and使用扫描隧道显微镜（STM），以及n-Chase混合物的两种含量混合物。在n =奇数的NCB中，仅观察到单层中的单行比对。 NCB与N =的单层对齐，即使在另一方面也显示出双行特性。对于NOCB而言，这些趋势相反，即n =均匀的单拖和n =奇数的双行。所有观察到的方面清楚地表明碳数对酒精链的奇数影响。偶数效应的起源是由于垂直于基板平面的NCB和NOCB中酒精链的prana-Zigzag平面的取向。因此，奇数效应与通过这种方向与与底物的相互作用的强度密切相关。在NCB和NOCB中，对于N = ODD，酒精链的末端碳原子必须分别没有和刚性底物。这就是n =的相互作用，即使在NCB（NOCB）中也比N =奇数更强（弱）。这种差异基本上导致了两个不同的比对，即单行和双行。提出的模型已通过计算机模拟较少验证