FINE STRUCTURE MEASUREMENTS IN ENERGY ANGULAR DISTRIBUTION OF SECONDARY ELECTRONS FROM A (110) FACE OF COPPER

The energy angular distribution of secondary electrons from a (110) face of copper in the (010) azimuth is measured by means of a dynamical method. The plots exhibit numerous fine structure maxima. It can be shown that the maxima corresponding to all theoretically possible directions of reciprocal lattice vectors up to the 46th order may be found in every measurement; taking the whole results, maxima corresponding to directions of reciprocal lattice vectors up to the 148th order may be detected continuously. The correlation of the maxima to the crystal structure yields experimental values of the refractive index which depends on the energy of the secondary but is independent of the energy of the primary electrons. By means of this refractive index it is possible to determine the energy band of excited states above the vacuum level in the (010) direction of the wave vector, except an integration constant. Copyright © 1968 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim