MICRO- AND NANO-STRUCTURES IN SINGLE CRYSTALS OF LITHIUM NIOBATE CONTAINING LANTHANIDE ADMIXTURES

ABSTRACT Micro-size domain structures in lithium niobate single crystals containing lanthanide (Gd, Tm, Sm, Lu) admixture, grown under stationary and non-stationary conditions are studied by efficient and flexible Thixomet® image analyser. Regular fractal-type domain structures observed along the three Y-axes of the hexagonal crystallographic set-up are assigned to pinning of the domain walls at defects created under conditions of imbalanced crystallization of the doped melt. Characteristic types of domains have been found analysing the configurations of domains on optical and atomic force microscopic images of surfaces of different crystallographic orientations.