X-RAY TOPOGRAPHIC INVESTIGATION OF TUNGSTATE FLUX-GROWN KTIOASO4 CRYSTALS

White-beam synchrotron radiation and Lang topographic investigations o f non-linear optical crystal KTiOAsO4 have been carried out. It is sho wn that domains and growth striations are primary planar defects in tu ngstate flux-grown single crystals. By selecting the wavelength to act ivate anomalous scattering effect near the absorption edge of the As a tom, antiparallel ferroelectric domains are revealed, and in reflectio n pairs hkl and (hkl) over bar, the domains demonstrate contrast rever sal. The differences in integrated intensity from a pair of opposite d omains are also calculated and the harmonics in a Laue spot are given. Finally, the domain wall configurations are discussed in terms of the structural characteristics of KTiOAsO4.