Features of structural changes in mosaic Ge:Sb according to X-ray diffractometry and electron backscatter diffraction data

Abstract

The structural homogeneity and degree of perfection inherent to mosaic Ge:Sb samples were investigated. The modified methods for analyzing diffraction images of backscattered electrons (Kikuchi patterns) were used to reduce the influence of instrumental factors. The root-mean-square deformations in the local regions of separate grains and at the boundaries between them were determined using the value of the spatial frequency of the energy spectrum of two-dimensional Fourier transform of Kikuchi patterns. It is shown that the maximum values of deformations (∼3.5⋅10-3) are typical for local regions, which are usually located at the boundaries between subgrains. X-ray studies confirm obtained values of root-mean-square deformations.

Local distribution of strains in synthetic diamond crystals determined by the energy spectrum normalized parameters

“…According to the works [13][14][15][16][17] , it is known that crystal deformations lead to distortions in the intensity distribution of Kikuchi bands and, accordingly, have a characteristic shape for each investigated region (Figure 2a). Therefore, the local deformation εPV of the crystal for a certain crystallographic plane can be calculated based on the area under the Kikuchi band intensity profile I(r) (Figure 2b) using the empirical equation 13 :…”

“…Crystal deformations affect the spatial distribution of the intensity of Kikuchi patterns, and, accordingly, their Fourier energy spectra [14][15][16][17] . Fourier energy spectra also have a characteristic shape for each investigated region, as it is for intensity distributions of the Kikuchi bands.…”

“…Therefore, an important parameter of diamond crystals that should be taken into account is their deformations ε, which are calculated due to the change in the interplanar distance Δd/d. Among the methods for calculating the deformations of crystals, methods based on the analysis of Kikuchi patterns are especially promising, due to their high locality and non-destructive nature of research [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] . In particular, crystal deformations are determined based on an analysis of the shape of intensity bands profiles and on the basis of an analysis of the Fourier energy spectrum of the Kikuchi patterns.…”

“…The presented methods for analyzing Kikuchi bands profiles involve a comparison of the areas of bands profiles obtained from different regions of the same crystal with the profile area obtained from a reference (undeformed) region of the crystal 12,13 . In case of analyzing the parameters of the energy spectrum of Kikuchi patterns, the existing methods also use one region of the crystal as a reference, and deformations in other regions are calculated in relation to it [14][15][16][17] . However, the selection of an undeformed part of the crystal is difficult or impossible in many cases, which greatly complicates the comparison of deformations calculated for different crystals.…”