Formation of broccoli-like morphology of tantalum powder

“Broccoli”-like morphology of Ta powder was found when Ca reduces Ta2O5 in the molten CaCl2. It consisted of fine particles and branches, and it was different from the conventional spherical particles. The formation of this morphology depended on the stacking methods of the starting materials. Eight types of filling methods proved that the branch was formed when the CaO-enriched region was locally produced near the oxide.