Motion of individual atoms and mesoscopic structural dynamics on non-equillibrium surfaces

非平衡表面上单个原子的运动和介观结构动力学

基本信息

批准号：
07454064
负责人：
ARUGA Tetsuya
金额：
$ 5.06万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454064/
关键词：
surface alloy reaction dynamics scanning tunneling microscope coadsorption structural dynamics 表面超高真空 STM

项目摘要

In order to realize the direct observation of the dynamic motion of individual atoms and molecules on the non-equillibrium surfaces and to understand the underlying microscopic mechanism, we have developped a new variable-temperature scanned probe microscope. In order to study further on the surface dynamics, we have also conducted thermal desorption and high-resolution electron energy loss spectroscopy to investigate the ordering in the (NO+CO) coadsorption system on the Pd (100) surface.The scanned probe microscope developped in the present study can be operated under ultrahigh vacuum and at sample temperature from 100 to 1000K.Another important characteristic is its low-noise signal output. The vertical noise for the topographic imaging mode is 3pm (p-p), which enables the imaging of (100) and (111) surfaces of transition metals. This microscope can also be operated at tunneling current as low as 1pA, which enables imaging of low-conductivity materials such as organic crystals.The ordering in (NO+CO) /Pd (100) coadsorption system has been studied by low-energy electron diffraction, thermal desorption and vibrational spectroscopy preparatory to the application of the scanned probe microscope. We have found that NO and CO form stable mixed ordered phases and that an explosive CO2 formation reaction undergoes in the mixed ordered phases. A kinetic Monte Carlo simulation based on a lattice-gas model has been done to quantify NO-CO intermolecular interactions.We have also investigated on the H+H/Pd (100) reaction and found that the impinging H atoms force the preadsorbed H atoms to penetrate into Pd bulk (stamping absorption). The characteristics of the potential energy surface for the MH2 system was discussed.

为了直接观察到非设备表面上个体原子和分子的动态运动并了解基本的显微镜机制，我们已经开发了一种新的变量温度扫描探针显微镜。为了进一步研究表面动力学，我们还进行了热解吸和高分辨率电子能量损失光谱仪，以研究PD（100）表面（100）表面（NO+CO）CoadSorption System中的排序。在本研究中，在Ultrahigh Vacuum和Samples Pacte placte samem cymist of 100至1000k.An的样品中，在本研究中开发了扫描的探针显微镜。地形成像模式的垂直噪声为3pm（p-p），可以实现过渡金属（100）和（111）表面的成像。该显微镜也可以在低至1Pa的隧道电流下进行操作，该隧道电流可以通过低电导晶体（NO+CO） /PD（100）配合吸附系统的订购来进行成像，通过低能电子衍射，热脱附和振动光谱探测器的应用程序，研究了该系统。我们发现，没有和CO形成稳定的混合有序相，并且在混合有序相中发生爆炸性二氧化碳的形成反应。已经进行了基于晶格 - 气体模型的动力学蒙特卡洛模拟，以量化无分子间相互作用。我们还对H+H/PD（100）反应进行了研究，并发现撞击H原子会迫使前吸收的H原子渗透到PD散装中（压缩吸收）。讨论了MH2系统的势能表面的特征。