Volume 82, Number 6, June 2008
Article Number 66005
Number of page(s) 3
Section Condensed Matter: Structural, Mechanical and Thermal Properties
Published online 06 June 2008
EPL, 82 (2008) 66005
DOI: 10.1209/0295-5075/82/66005

Si self-diffusion in cubic B20-structured FeSi

I. Riihimäki1, A. Virtanen1, P. Pusa2, M. Salamon3, H. Mehrer3 and J. Räisänen2

1  Department of Physics, University of Jyväskylä - P.O. Box 35, FIN-40351 Jyväskylä, Finland, EU
2  Department of Physics, University of Helsinki - P.O. Box 43, FIN-00014 Helsinki, Finland, EU
3  Institut für Materialphysik, Universität Münster - Wilhelm-Klemm Strasse 10, D-48149 Münster, Germany, EU

received 25 March 2008; accepted in final form 5 May 2008; published June 2008
published online 6 June 2008

Self-diffusion of implanted 31Si in the $\varepsilon$-phase FeSi (cubic B20-structure) has been determined in the temperature range 660$\hbox{--}$ 810 $^{\circ }$C using the modified radiotracer technique. With an activation enthalpy of 2.30 eV and a pre-exponential factor of 15$\times$10-8 m2 s-1 the silicon diffusivity was found to be slightly slower than Ge impurity diffusion in FeSi. This difference is proposed to originate from attractive elastic interactions prevailing between the slightly oversized Ge atoms and the Si sublattice vacancies. The results confirm the argument that 71Ge radioisotopes may be used to substitute the short-lived 31Si radiotracers when estimating self-diffusion in silicides.

66.30.H- - Self-diffusion and ionic conduction in nonmetals.
66.30.J- - Diffusion of impurities.

© EPLA 2008