A persistent problem in the synthesis of complex materials from three or more constituents is the retention of very stable intermediate phases with properties grossly different from the target phase. In a recently developed two-stage synthesis methodology, a binary precursor is prepared and then directly converted into the product phase, thereby avoiding intermediate phase formation. Crystallographic similarities between he precursor and product phases are manipulated such that the major structural elements remain chemically intact. Ordered structural vacancies are used to facilitate rapid and highly selective diffusion of the third element into the precursor. Since no crystallographic reconstruction is required, no extraneous phases can form. The method has been tested on the solid state synthesis of Si3SiC2 and Ti23AlC2.
