C49 and C54 TiSi2 films were implanted with 200 keV 5 x 10(14) cm(-2) xenon (Xe+) ions at -185 degrees C, and the regrowth of C49 and C54 TiSi2 grains was studied following thermal annealing. The low-temperature Xe+ implant resulted in partial amorphization of the C54 TiSi2 layer, as evidenced by transmission electron microscopy. Upon annealing at temperatures below similar to 600 degrees C, a double-layer structure was obtained consisting of a C49 TiSi2 layer on top of C54 TiSi2. For an equivalent Xe+ implant in C49 TiSi2, the C49-C54 transition temperature was delayed as compared with the phase transition for a nonimplanted C49 TiSi2 film. Following room-temperature implantation of C49 TiSi2 with 100 keV germanium (Ge+) ions at various doses (1 x 10(14) to 1 x 10(16) cm(-2)), or low doses of 70 keV Xe+ (1 x 10(12) and 1 x 10(13) cm(-2)), no reduction in the C49-C54 transition temperature was observed upon thermal annealing. According to our results, defects caused by Xe+ or Ge+ ion implantation of C49 TiSi2 do not promote formation of C54 TiSi2.