Electrochemical synthesis of Nb5Si3 intermetallic compound from molten calcium chloride salt

Nb5Si3 intermetallic compound was directly synthesized via an electrodeoxidation process from molten CaCl2 electrolyte. The reaction mechanism was studied by performing a series of quenching investigations, which suggested that the formation of a series of sub oxides and compounds containing calcium and oxygen preceded the formation of Nb5Si3. While Nb2O5 was gradually reduced to its sub oxides, (Nb2O5/NbO2/NbO/Nb), SiO2, on the other hand, got directly reduced to silicon and reacted with Nb to form Nb5Si3.

► Nb5Si3 was directly synthesized via electrodeoxidation in molten CaCl2.
► Nb2O5 was gradually reduced to NbO2, NbO and Nb.
► CaNb2O6 was formed at the initial stage and reduced to CaNb2O4 and Nb.
► The formation of Nb5Si3 impelled the decomposition of SiO2.