C49-C54 phase transition in nanometric titanium disilicide nanograins

The first order C49-C54 phase transition was studied in single TiSi grains embedded in a Si matrix by transmission electron microscopy and X-ray diffraction. The fraction of material transformed into C54 was determined at different times during the annealing in the 700-1100 °C temperature range. The fraction of C54 increases with temperature and the steady state value is reached in times of about 60 s. The data are interpreted in terms of heterogeneous nucleation at the silicide-silicon interface.