EFFECTS OF MENISCUS ON THE DIRECTIONAL GROWTH OF POTASSIUM NIOBATE SINGLE-CRYSTALS

The study of meniscus effects on the directional growth of single crys tals of potassium niobate (KNbO3) with a [110](pc) oriented seed by th e top-seeded-solution-growth technique has been described. The directi onal growth of KNbO3 single crystals has been illustrated for differen t crystallographic orientations of the crystal. Experimental results s how that the shape of the solution flux meniscus, which is determined by a number of growth parameters, has a significant effect on growth r ates on different {100}(pc), {010}(pc) and {001}(pc) type surfaces. Fi ndings based on this work enable one to select a dominant growth direc tion and hence to engineer the geometrical shaping of resultant KNbO3 single crystals through careful control of growth parameters. Maximum crystal dimensions for the grown KNbO3 along [100](pc) and [001](pc) a chieved in this work are 34.0 and 31.2 mm, respectively.