A study on the indexing method of the electron backscatter diffraction pattern assisted by the Kikuchi bandwidth.

Abstract

In this study, a new method is established for indexing electron backscatter diffraction (EBSD) patterns assisted by the Kikuchi bandwidth. This method utilises both interplanar angles and interplanar spacings to determine the Miller indices of the Kikuchi bands in EBSD patterns to improve the efficiency and precision of indexing in the EBSD system. Two samples of single-crystal silicon were investigated to validate the method based on (a) the detection of the edges of the EBSD Kikuchi bands and (b) the calculation of the Kikuchi bandwidths. The relationship between the Kikuchi bandwidth and the interplanar spacing at different positions was established, and the interplanar spacing of the corresponding lattice plane of each Kikuchi band was calculated with the use of the Kikuchi bandwidth information. The relative errors between the theoretical and experimental interplanar spacings are small, with an average relative error of 2.6% and a minimum relative error of 1.04%. The results indicated that the Miller index of each Kikuchi band can be determined accurately with this new method. It is demonstrated that use of this new method improves the efficiency and accuracy of the EBSD system. LAY DESCRIPTION: Electron backscatter diffraction (EBSD) is a scanning electron microscope-based technique. In our work, a new method is established for indexing EBSD patterns assisted by the Kikuchi bandwidth. This method utilizes both interplanar angles and interplanar spacings to determine the Miller indices of the Kikuchi bands in EBSD patterns to improve the efficiency and precision of indexing in the EBSD system. Two samples of single-crystal silicon were investigated to validate the method based on a) the detection of the edges of the EBSD Kikuchi bands and b) the calculation of the Kikuchi bandwidths. The relationship between the Kikuchi bandwidth and the interplanar spacing at different positions was established, and the interplanar spacing of the corresponding lattice plane of each Kikuchi band was calculated with the use of the Kikuchi bandwidth information. The relative errors between the theoretical and experimental interplanar spacings are small, with an average relative error of 2.6% and a minimum relative error of 1.04%. Compared with the results reported in the literature, the width-assisted Kikuchi pattern indexing method can well distinguish some cases with similar angles, and reduce the possibility of mis-indexing. After the introduction of the width information of the Kikuchi bands, the screening range can be narrowed by determining the crystal plane family, and the efficiency and accuracy of the indexing process can thus be improved. Specifically, for some materials with increased symmetry, such as cubic crystal materials, it is necessary to use the interplanar spacing for indexing when the interplanar angles are not diagnostic. The results indicated that the Miller index of each Kikuchi band can be determined accurately with this new method. It is demonstrated that use of this new method improves the efficiency and accuracy of the EBSD system.