METHOD FOR PRODUCTION OF SINGLE CRYSTALS OF POTASSIUM AND NIOBIUM SILICATE Russian patent published in 1997 - IPC

FIELD: methods of production in hydrothermal conditions of single crystals K₂(NbO)₂Si₄O₁₅ used in nonlinear optics. SUBSTANCE: method includes synthesis carried out in hydrothermal conditions at temperature of 400-600 C and pressure of liquid phase of 900-1300 atm with ratio of mixture components Nb₂O₅/ SiO₂ (1:1)-(1:5). Solution is used in form of aqueous solution of KOH, or KF or K₂CO₃ of mixture of KOH with KF, KOH with K₂CO₃, or KOH with KF and KCl. Method involves production of single crystals sizing up to 2-3 mm with no need of use of such expensive materials as platinum, production of single crystals suitable for measuring their physical properties and application of the produced single crystals in form of seeds for growing large single crystals for use in the capacity of nonlinear optical material. EFFECT: higher efficiency.