Variation of Electron Diffraction Intensity with Crystal

Abstract

Intensity of electron diffraction Debye-Scherrer rings was studied for evaporated films of Al, Ag, Au, NaCl, KCl and MgO of various thicknesses and crystal sizes. The observed intensity deviates from the value calculated by the kinematical theory of diffraction at crystal sizes less than 100 Å for all the materials examined. This result agrees with the conclusion of Blackman's dynamical theory (Proc. Roy. Soc. 173 (1989) 68). Yamzin & Pinsker's conclusion (Dokl. Akad. Nauk 65 (1949) 645) that the kinematical theory can hold for films of thickness up to 500 Å, apparently contradicts the present result. It was pointed out that Yamzin & Pinsker's conclusion resulted from the fact that they neglected the effect of the temperature factor.