C49 defect influence on the C49?C54 transition

The C49-C54 transformation has been studied in TiSi2 thin films having different concentration of defects. The defect concentration in the C49 phase has been varied using different thermal processes in the 460-540 degreesC temperature range; in fact, the defect concentration decreases with increasing the temperature and/or the duration of the thermal process as attested by the large variation of the silicide residual resistivity at 4 K. The kinetics of the transformation at 650 degreesC has been followed by in situ resistivity measurements and, for each sample, the transition time decreases as the defect concentration in the metastable phase decreases.