Synthesis of nanoscale particles of Ta and Nb₃Al by homogeneous reduction in liquid ammonia

The analysis of metallothermic reduction as an electronically mediated reaction predicted that the particle size of solid product could be reduced if the reaction were conducted in a medium that is a mixed conductor (ionic and electronic). This prediction was confirmed by reacting TaCl₅ with sodium, each dissolved in liquid ammonia, to produce tantalum powder having an average particle size over an order of magnitude finer than the micron-sized powders produced commercially today. Metallothermic reduction in a mixed conducting medium has been extended to a multicomponent system in order to synthesize nanosized powder of Nb₃Al by co-reduction of NbCl₅ and AlCl₃ both dissolved in liquid ammonia.