Chemical synthesis of BaCO3 with a hexagonal pencil-like morphology

Uniform hexagonal pencil-like BaCO₃ whiskers have been successfully synthesized by the chemical reaction of barium chloride and urea via a facile hydrothermal route. Most whiskers have well-defined crystallographic facets and a regular prismatic hexagon with the length up to 50 μm and diameter around 5 μm. The straight pencil-like BaCO₃ whisker is grown along the c-axial direction, the six faces of whiskers are consisted of both {0 1 0} and {1 1 0} planes. The present hydrothermal synthetic system tends to provide an appropriate chemical microenvironment for the formation of hexagonal pencil-like BaCO₃ whiskers, due to the fact that the homogeneous decomposition of urea plays an essential role in the whole process.