X-RAY STRUCTURAL STUDIES OF LITHIUM NIOBATE CRYSTALS DOPED WITH PRASEODYMIUM

The structural features of LiNbO3 crystals doped with praseodymium in the concentration range from 0.008 to 0.25 mol% were studied using X-ray diffraction methods. The study showed that praseodymium atoms occupy vacant lithium positions in the structure of the crystals under study. As the concentration of praseodymium increases, the nature and distribution of intrinsic defects change. The sample obtained at a concentration of 0.25 mol% has the greatest structural heterogeneity: the concentration of Nboct defects is maximum, these defects lead to disordering of the cation sublattice, in addition, strong distortions of the LiO6 and NbLiO6 octahedra are observed.