Intermediate phase in synthesis of TiSi2 by mechanical alloying and annealing

The alloying process by mechanical milling and subsequent annealing of a 1:2 mole ratio Ti/2Si system has been analyzed from a crystallographic viewpoint. An intermediate phase appeared after prolonged milling or prior to the formation of TiSi2 on annealing. The observed XRD pattern of the intermediate phase was coincident with that of a structure constructed by introducing a stacking fault on the close-packed plane of the hexagonal Ti lattice with partial replacement of Ti by Si atoms. The structure of TiSi2 is formed from the intermediate phase by an interchange of Ti with Si atoms on the close-packed plane, being associated with structural relaxation.