权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

X-ray Structural Analysis of the Monolayrs Adsorbed on Solid Surfaces

固体表面吸附单分子层的 X 射线结构分析

基本信息

批准号：
05453056
负责人：
INABA Akira
金额：
$ 4.74万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

The momolayr of some simple molecules, which is physically adsorbed on a homogeneous surface of solids such as graphite, forms a two-dimensional molecular solid at low temperatures. We investigate the system by calorimetry, diffraction and neutron scattering. Such adsorbed monolayrs often exhibit phase transitions in the solid phase, which is similar to the case of the bulk solid. However, since the balance of the molecular interactions in this system is rather subtle, many phases appear depending upon the coverage and the temperature.The systems that we investigated were the monolayrs of isotopic methanes, neopentane, adamantane, sulfuryl fluoride, sulfur hexafluoride, camphor, tetrakis (methylthio) methane and others. All the molecules have globular shape and the orientational ordering at low temperatures is particularly interesting. The X-ray diffraction patterns were obtained for the monolayrs of adamantane, sulfur hexafluoride, camphor and tetrakis (methylthio) methane at ambient and low temperatures. The neutron diffraction patterns were also obtained for the monolayrs of fully-deuterated neopentane, fully-deuterated adamantane and sulfur hexafluoride at low temperatures.While the detailed structural analysis is now under way, the mechanism of the phase transitions seems to be of orientational order-disorder type. The nature of the phase transition of neopentane monolayr was investigated by inelastic and quasielastic neutron scattering. The dynamics in methane monolayrs were investigated by the rotational tunneling spectra observed by inelastic neutron scattering. Investigation of the dielectric properties of the monolayrs, which is our anotherproject, is now in progress by using hexagonal boron nitride as an adsorbent.

一些简单分子的单分子层物理吸附在固体（如石墨）的均匀表面上，在低温下形成二维分子固体。我们用量热法、衍射法和中子散射法研究了这个系统。这样的吸附单层经常表现出在固相中的相变，这是类似于散装固体的情况。然而，由于在这个系统中的分子间相互作用的平衡是相当微妙的，许多相出现依赖于覆盖率和temperature.The系统，我们调查的是同位素甲烷，新戊烷，金刚烷，硫酰氟，六氟化硫，樟脑，四（甲硫基）甲烷和其他的单层。所有的分子都是球形的，在低温下的取向有序是特别有趣的。金刚烷，六氟化硫，樟脑和四（甲硫基）甲烷在环境温度和低温下的单层的X射线衍射图。在低温条件下，获得了全氘代新戊烷、全氘代金刚烷和六氟化硫单层膜的中子衍射花样，详细的结构分析正在进行中，相变机制可能是取向有序-无序型的。用中子非弹性和准弹性散射研究了新戊烷单层膜的相变性质。用中子非弹性散射的转动隧穿谱研究了甲烷分子膜的动力学。我们的另一个研究项目是利用六方氮化硼作为吸附剂来研究单层膜的介电性质。