TY - JOUR A1 - Winkelmann, Aimo A1 - Nolze, Gert T1 - Analysis of Kikuchi band contrast reversal in electron backscatter diffraction patterns of silicon N2 - We analyze the contrast reversal of Kikuchi bands that can be seen in electron backscatter diffraction (EBSD) patterns under specific experimental conditions. The observed effect can be reproduced using dynamical electron diffraction calculations. Two crucial contributions are identified to be at work: First, the incident beam creates a depth distribution of incoherently backscattered electrons which depends on the incidence angle of the beam. Second, the localized inelastic scattering in the outgoing path leads to pronounced anomalous absorption effects for electrons at grazing emission angles, as these electrons have to go through the largest amount of material. We use simple model depth distributions to account for the incident beam effect, and we assume art exit angle dependent effective crystal thickness in the dynamical electron diffraction calculations. Very good agreement is obtained with experimental observations for silicon at 20 key primary beam energy. KW - Electron backscatter diffraction KW - Kikuchi patterns KW - Dynamical electron diffraction simulation PY - 2010 U6 - https://doi.org/10.1016/j.ultramic.2009.11.008 SN - 0304-3991 VL - 110 IS - 3 SP - 190 EP - 194 PB - Elsevier CY - New York, NY AN - OPUS4-24008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Winkelmann, Aimo T1 - Progress in dynamic EBSD pattern simulation N2 - EBSD is nowadays a common technique for the characterization of crystalline microstructures in scanning electron microscopy. The diffraction patterns are often interpreted by superimposing individual Kikuchi bands which are geometrically described by band edges derived from Braggs law. For the typically very simple crystal structures of technically applied materials, such a simplification of the Kikuchi pattern interpretation works sufficiently well, especially for orientation determinations as a main application of EBSD. The more complex crystal structures, however, are a challenge for EBSD indexing routines which in such cases often fail unpredictably. The use of only the intensities of single reflectors for a description of the Kikuchi band intensity and as a cut-off criterion for a pre-selection of the strongest bands are not satisfactory. Often the result will match too many phases, or there are certain deviations in the intensity prediction which must be adapted manually. This is already problematic if one is absolutely sure that the patterns are originating from the expected phase and it becomes a very questionable procedure for an unknown phase. KW - Electron backscatter diffraction KW - Dynamical simulation KW - Geometrical model KW - Kinematic approach KW - Intensity PY - 2010 U6 - https://doi.org/10.1017/S1431927610063324 VL - 16 IS - Suppl. 2 SP - 62 EP - 63 PB - Microscopy Society of America AN - OPUS4-38000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -