Diffusion of Si and Ge in the Intermetallic Phase Fe_3Si: Ion Implantation and SIMS Studies

摘要

Diffuson of silicon and germanium in the D0_3 phase of the system Fe-Si has been studied. As there is no radioactive Si isotope for detailed self-diffusion studies the rare stable isotope ~(30)Si was used. Tracer deposition was done by ion implantation. Profiles were analysed by means of secondary ion mass spectrometry (SIMS). In a preceding study the radioisotope ~(71)Ge served as a substitute for Si. One experiment with the short-lived ~(31)Si showed very similar diffusion rates for Si and Ge, so that the approach of using the homologous element seemed to be appropiate. As a check for this approach we also performed diffusion experiments with the stable isotope ~(74)Ge in analogy to those with ~(30)Si. The obtained data confirms the strong asymmetry between the diffusion of majority and minority constituents in D0_3 phases. The data also shows the homology of Ge and Si. Finally this demonstrates that radiotracer methods and SIMS technique can be successfully combined in order to cover a large temperature interval.