Ion beam synthesis of ternary phase CoFe‐silicide in (111) silicon

A transmission electron microscopy (TEM) investigation is presented of ion beam synthesized buried CoFe‐silicide prepared by sequential equal‐dose implantations of both metals. The TEM analysis shows strong evidence for the formation of a metastable ternary Co0.5Fe0.5Si2 phase during the implantation. Annealing of these structures at 1000 °C results in the formation of a continuous buried layer, but phase separation occurs into B‐oriented CoxFe1−xSi2 and twinned α‐FexCo1−xSi2 (both with x close to 1).