A continuous buriedGdSi1.7layer is formed by channelled implantation of 90 keV Gd ions into Si(111). In the case of (001) oriented silicon substrates, the silicide film is formed on the silicon surface. Its worse crystalline quality is due to the epitaxy occurring relative to all four{111}Siplanes resulting in a texturedGdSi1.7layer. Annealing at a temperature of ⩾850 °C for 30 min results in the presence of only the orthorhombicGdSi2phase on the silicon surface for both (111) and (001) silicon substrates. However, the precipitates embedded in the silicon substrate are still hexagonalGdSi1.7.The phase transformation temperature is higher for (111) than for (001) silicon. ©1997 American Institute of Physics.