Three-dimensional atomic-resolution holograms of Ag(111) and Ag(100) by quasi-elastic electron

• Main Authors: Jeng; Pei Ren, 鄭培仁
• Other Authors: Chou Ya Chang
• Format: Others
• Language: en_US
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/74684902632603009288

碩士 === 國立清華大學 === 物理研究所 === 81 === We demonstrate a method of direct structrure determination using Fourier transformation with experimental quasi-elastic electron diffraction patterns. High resolution of about 1A, high fidelity and artifact-free images of Ag(111) andcrystal surface atoms in three dimensions are obtained by using a multiple-energy phase-summing method. In this method, which Fourier transforms the energy spectra in every directions, multiple scattering effect of electrons is suppressed. No preceding knowledge of the structure studied and quantum mechanical calculations are needed. In addition to the time- saving calculations, unlike the photoelectron holography, this technique is easy-established in a conventional surface science laboratory without using synchrotron radiation sources, the data acquisition is rapid and not difficult. We would point out that the electron-emission holography is pratical not only in theory but also in our experiment, and illustrate that the direct method of determination of near surface structure is possible.