Structural changes and phase transitions during high dose Si implantation into single crystal Ni(100) and subsequent annealing at temperatures up to 800 °C have been characterized using Rutherford backscattering spectrometry and channeling. A complete amorphous layer is produced after implantation to doses above about 4.5×1017Si/cm2. The recrystallization of the amorphous layer during isochronal annealing leads to the formation of various Ni‐rich silicides at different temperatures. Ion channeling suggests that an epitaxial Ni3Si layer on the Ni(100) substrate can form at a temperature of 400 °C. Further annealing at higher temperatures up to 600 °C improves the epitaxial quality, as indicated by a channeling minimum yield &khgr;minof 8% in the Ni3Si layer. Higher temperature annealing at 700 °C and above results in the dissolution of the Ni3Si layer into the Ni substrate.