| Summary: | 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.
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