Growth of CaTiO3dendrites and rectangular prisms through a wet chemical method

Abstract

Dendrites and rectangular prisms of orthorhombic CaTiO₃ were synthesized massively by reacting titanium tetraisopropoxide with Ca(OH)₂ in basic solutions at 120 °C. Dendrites were formed in dilute base solution with moderate stirring while rectangular prisms were formed in concentrated base solution or with vigorous stirring. The 3-D hierarchical dendrites are constructed by a main branch, from which two side branches grow 48° to the trunk. The growth directions of the branches were identified to be {102} and {012). On the other hand, the CaTiO₃ rectangular prisms have {110}, and {001} facets and a longitudinal direction along the normal vector of the {001} planes. The formation of the two distinct morphologies results from different growth behavior. Under non-equilibrium conditions, interface kinetics markedly affects the reaction, resulting from pressure field, heat flow, and crystal orientation, which leads to the formation of complex morphology dendrite. Under equilibrium conditions, thermodynamics dominates the reaction, resulting in exposing of the most stable plane, which leads to the formation of rectangular prisms.