A STUDY OF INCLUSIONS AND DISLOCATIONS IN LiNbO3 CRYSTALS BY X-RAY TOPOGRAPHY

The inclusions and dislocations in LiNbO3 crystals have been studied by means of X-ray topography. The influence of elastic anisotropy on the contrast of inclusions was observed. The Burgers vectors of dislocations in this crystals were found to be of the type of 1/3〈1120〉, the smallest lattice vector, and 1/3〈0111〉, the next smallest lattice vector. The pure twist sub-boundary which consists of two sets of pure screw dislocations with Burgers vectors l/3〈101l〉 was also observed.