Quantitative TDS absorption corrections for LACBED patterns from GaP and InAs

Abstract

Large-angle convergent-beam electron diffraction (LACBED or Tanaka) patterns have been measured at 200 keV and room temperature for the 〈332〉 zone axis for the III-V semiconductors GaP and InAs. Bright-field LACBED patterns exhibit substantial differences in contrast. We demonstrate that a quantitative Einstein model for absorption due to thermal diffuse scattering (TDS) provides the most important contribution to differences in diffraction contrast rather than structure factor variations due to differences in atomic number. The absorptive potential for InAs is roughly a factor of two larger than for GaP. © 1992.