GROWTH AND REAL STRUCTURE OF KTIOASO4 CRYSTALS FROM SELF-FLUXES

The peculiarities of KTiOAsO4 crystal growth from self-fluxes with a K /As ratio ranging from I to 2 were investigated The arsenates crystall ized in the ternary system KTiOAsO4-KAsO3-K4As2O7 in the temperature r ange 500-1000 degrees C were identified. The simultaneous crystallizat ion of KTiOAsO4 and K4As2O7 from the solvent with K/As = 1.67 was obse rved. The KTiOAsO4 dissolve heats of 8 and IO kcal/mol were defined fr om DTA data when, correspondingly, the ratio of K/As was 1.5 and 1.67 in the flux. The real structure of grown crystals was investigated by reflectance X-ray diffraction and topography. As a result, optical qua lity single-domain KTiOAsO4 crystals with a FWHM of 12 arcsec and a di slocation density < 10(2) cm(-2) were demonstrated.