STM数据采集分析计算机系统

COMPUTER SYSTEM FOR SCANNING TUNNELING MICROSCOPE

扫描隧道显微镜(STM)是1982年问世的研究物质表面结构的新型仪器,近几年来得到了很大的发展。与其它各种类型的显微镜相比,它的最大优点是具有较高的分辨率(平行和垂直于样品表面方向的分辨率分别可达1和0.1),共弱点是数据的处理和显示功能不强。发展STM的自动控制、数据采集、实时显示和数据分析的计算机系统,对于改进仪器的性能至关重要。本文介绍我们研制的一套STM数据采集、存储、实时显示和数据分析系统,并以用该系统采集的高取向石墨数据为例,介绍系统的软件功能。

The scanning tunneling microscope (STM)is a powerful instrument which provide surface topographic images down to the atomic scale and spectroscopic information on the surface density of electronic states. A computerized system based on the IBM Personal Computer Model XT or AT for STM control, data acquisition and display is presented. The high resolution digital-to-analog converter card and analog-to-digital converter card are used for the computer to generate the voltages applied to the STM piezoelectric elements and to measure the tunneling current. A high resolution graphics controller card is used for real-time display of the STM 'images'. The software that performs the control, data acquisition and display of the STM has been written in FORTRAN and linked with some ASSEMBLER subroutines for the critical tasks in roder to get a fast and compact executable module which works under DOS Version 3.2. Some images analysis and display tool are included for a posterior image processing.