On the Investigation of the Structure of Amorphous Substances by Means of Electron Diffraction

Abstract

A "Scanning High Energy Electron Diffraction"-(SHEED-)apparatus is described with which the intensity curves of elastically scattered electrons are obtained within a few minutes. The elimination of the inelastic background is done by means of an electrostatic filter with an energy resolution of 10 4 , which is only limited by the line width of the beam producing system. The intensity curves obtained experimentally are corrected for multiple scattering.The pair correlation functions of amorphous Germanium as obtained by electron and X-ray diffraction are compared. The electron diffraction curves agree well with the corresponding curves of other authors. The same stands for the curves obtained with X-rays. The differences between the curves obtained with electrons and X-rays are discussed.

Investigation of the Structure of Amorphous Substances by Means of Electron Diffraction

“…4 we present again this corrected curve (--) and compare it with the X-ray scattering result from [9] (---) and the neutron scattering result from [10] (• • • •)• The accordance between these three structure factors, which were obtained with three different radi ations, is surprisingly good. Compared to [1] accordance was mainly achieved by the following items:…”

“…Compared to the ex perimental facility as used in a previous work [1] we describe in the present paper the use of a commercial electron microscope equipped with a so-called omegafilter. Useful energy filtering has earlier been applied to the study of amorphous materials by Cockayne et al [2] and Reimer et al [3].…”

“…In the present study for the first time an imaging omega filter and a slow scan CCD-camera as detector was applied. Concerning the correction for multiple scattering, the method applied in [1,4] is improved.…”

Atomic Structure of Amorphous Metallic Ni81B19

“…This method, a combination of neutrons, X-rays, and electrons, fails due to principal difficulties in the quantitative evaluation of the total structure factor from electron diffraction ( [10] and [11]). …”

“…The experimental G^iB(R) is again plotted as solid line. This curve was fitted by a sum of Gaussian curves, plotted as dashed curve ( R) 10 …”