A NEW FLUX FOR THE RAPID GROWTH OF POTASSIUM TITANYL PHOSPHATE (KTiOPO4) SINGLE CRYSTAL. M. T. Sebastian, S. Suma, N. Santha, Electronic Ceramics Division, Regional Research Laboratory, Thiruvananthapuram-695 019, India

Single crystals of the well known non-linear and electro-optic material KTiOPO₄(KTP) has been grown using a new barium-potassium based complex phosphate flux. The solubility of KTP in this new flux is higher at high temperatures and low at low temperatures as compared to the conventional flux K₆P₄O₁₃. The new flux is less viscous and hence avoids the problem of glass formation and a higher cooling rate can be given. Good quality crystals of KTP up to 6mm in size can be grown in a day by giving a cooling rate of 120 deg.C/day. The KTP crystals grown in this new flux are transparent, free of inclusions or elements from the flux and OH incorporation. The use of this flux indicates the possibility of growing relatively large crystals commercially in a short time.