Numerical convergence of dynamical calculations of reflection high-energy electron diffraction intensities

Abstract

Numerical convergence of multi-slice dynamical calculations of reflection high-energy electron diffraction (RHEED) intensities for numbers of slices, atomic layers and beams is reported for a Ag(001) surface. Criterions of the convergence for numbers of slices and atomic layers are delivered by a thermal vibration amplitude of atoms and an electron absorption coefficient, respectively. From comparison of the curves of 11-beam calculation for the zeroth Laue zone and those of 61-beam calculation with higher order Laue zones, it is revealed that low-order RHEED intensities obtained by the 11-beam calculation are not significantly different from those of the 61-beam calculation. Therefore, calculated RHEED intensities for the zeroth Laue zone spots are obtained well by dynamical calculation with a beam set in only the zeroth Laue zone. Effects of the Debye-Waller factor on RHEED intensities of higher order Laue zones are also discussed.