Investigation of the defects distribution along the growth direction in GdCOB crystals by synchrotron and conventional X-ray topography

The GdCa4O(BO3)3 single crystals of monoclinic structure grown by the Czochralski technique were investigated by the synchrotron radiation white beam (SRWB) and conventional X-ray topography. The samples cut out parallel to the crystal growth axis b have been investigated in order to reveal the distribution of defects along the growth axis. Dislocations bundles, correlated with periodical changes of crystal diameter and large volume defects have been observed. The white beam synchrotron projection topography allowed better recognition of many details of the defect structure.