Intrinsic LiNbO₃ melt species partitioning at the congruent melt composition. III. Choice of the growth parameters for the dynamic congruent-state growth

During crystal growth from a stirred melt, partitioning of the intrinsic LiNbO₃ melt species is significantly influenced by the interface electric field caused by the thermoelectric power and the charge separation effects (crystallization EMF) which are a function of growth parameters such as solute boundary layer thickness, δ_C, growth velocity, V and temperature gradient, G_L. Thus, combinations of δ_C(g), V(g) and G_L(g) were calculated as a function of solidified melt fraction, g, by using a nonlinear programming technique 'polytope method', which leads to the true dynamic congruent-state growth from a finite amount of melt, i.e. a growth with an almost constant composition throughout the crystal and very little amount of uncoupled ionic species contained in the crystal. The micro-pulling-down technique is the most suitable growth method which can meet the calculated growth conditions.