X-ray Diffraction Topography - Investigation of Single Crystals Grown by the Czochralski Method

Abstract

X-ray diraction topography is one of basic diagnostics tools serving for visualisation of single crystal lattice defects. Defects of various kinds can be observed. The present study is a review of topographic results obtained in the X-ray laboratory of the Institute of Experimental Physics, University of Warsaw, for three families of single crystals grown by the Czochralski method: (i) silicon (Si) and Si1−xGex, (ii) selected binary REVO4 oxides and (iii) selected ternary ABCO4 oxides. The eect of chemical composition, growth conditions and post growth thermal annealing on the defect appearing in crystals is discussed. Various defects are revealed: the growth dislocations (some early Si crystals), the composition-gradient-induced lattice deformation (Si1−xGex, solid solutions CaxSr1−xNdAlO4), defects generated in Si after the post growth thermal processes, oriented elongated rod-like macro-defects tending to form networks within the crystal core, cellular structure in the outer shell (SrLaGaO4), and variously developed block structure (in selected binary REVO4 crystals).

Characterization of crystal lattice defects in calcium molybdate single crystals (CaMoO4) by means of X‐ray diffraction topography

“…The revealed block structure is most probably caused by cracking of the CMO crystals connected with thermal stresses introduced by nonuniform cooling. The presently observed defect structure appears to be very similar to those found in YVO 4 and GdVO 4 crystals grown by the Czochralski method …”

“…The presently observed defect structure appears to be very similar to those found in YVO 4 and GdVO 4 crystals grown by the Czochralski method. [25][26][27][28][29][30]…”

“…These methods are very sensitive to the lattice deformation and are very effective for studying of various oxide crystals grown by Czochralski method. [25][26][27][28][29][30] Experimental Calcium molybdate single crystals have been grown by means of the Czochralski technique in the Institute of Electronic Materials Technology in Warsaw. The samples in the form of plane parallel plates, cut off perpendicularly to the crystal growth axis, had been mechanically and chemically polished.…”

“…The aim of the present study was the characterization of crystal lattice defects in CaMoO 4 crystals by means of synchrotron and conventional X‐ray diffraction topography completed by recording of high‐resolution diffraction curves. These methods are very sensitive to the lattice deformation and are very effective for studying of various oxide crystals grown by Czochralski method …”