Investigation of chemical micro-inhomogeneities in Bi100−xSbx single crystals

Double-crystal topography, electron-beam microanalysis, and electrolytical etching are used for characterizing the micro-inhomogeneities of the antimony concentration in zone-levelled Bi100–xSbx single crystals. The double-crystal topography detects the micro-inhomogeneities by means of lattice-constant variations, whereas the electron-beam microanalysis utilizes the intensity variation of the characteristic X-radiation. All the methods employed yield a periodic striated structure, being in good agreement with each other. The striation distances vary from 1 to 400 μm, the detected variation amplitudes ranging within 0.05 ≦ Δx ≦ 0.25. The detected micro-inhomogeneities can be attributed to different growth-conditioned causes.