Abstract :
The procedure of molten salt synthesis (MSS) could be potentially used to synthesize a range of complex oxides used by the refractory industry. Two reaction mechanisms, “template-growth” and “dissolution-precipitation”, are involved in MSS. The former functions when one reactant is soluble but another much less-soluble in the salt, whereas the latter functions when the two reactants are both soluble in the salt. In the former, the more soluble reactant dissolves in the salt, diffuses onto the surface of the less soluble reactant, and then reacts to form the product particles which retain the morphologies and sizes of the less soluble reactant, whereas in the latter, the product phases precipitate from the salt oversaturated with the two reactants, and often show different morphologies and sizes from those of the reactants. By using appropriate morphologies/size of raw materials and salt assemblies, complex refractory oxides with desirable morphologies and sizes could be prepared at much lowered temperatures up to 1000oC lower than those used by the Conventional Mixed Oxide Synthesis (CMOS).
