MICROBUBBLE FORMATION DURING CRYSTALLIZATION OF LINBO3 MELTS

Bubbles whose size ranged from sub-micron to similar to 1 mu m were ob served along the interface in the interface liquid boundary layer of L iNbO3 melts when fiber-shaped LiNbO3 crystals were grown via laser-hea ted pedestal growth (LHPG). This method usually yields a very high tem perature gradient near the solid-liquid interface leading to significa nt thermoelectric power which affects the distribution of LiNbO3 intri nsic species in the melt. Supersaturation of OLi- and/or O2- ions at t he interface were calculated to have a large enough total supersaturat ion to nucleate bubbles due to a combination of both solute build up a nd a significant temperature difference between the interface and the far-field liquid.