Diffusion in molybdenum disilicide

The radiotracer ⁷¹Ge was used to study diffusion in oriented single crystals of MoSi₂. Ge was chosen in order to simulate Si self-diffusion. ⁷¹Ge was produced by neutron activation and implanted below the sample surface. Diffusion was measured for two different orientations of single crystals with the tetragonal C11_b crystal structure. The diffusion annealings were carried out in a temperature range of 900 K to 1250 K. We found a surprisingly fast Ge diffusion and a relatively high anisotropy. Diffusion perpendicular to the tetragonal axis is faster by about a factor of 5. The activation enthalpies are similar (about 190 kJ mol^-1) for both principal directions.

Beteiligte Wissenschaftler:

Dr. K. Freitag (Universität Bonn), Dr. K. Ito (Kyoto University, Japan), Prof. Dr. H. Mehrer (Leiter), Dipl.-Phys. M. Salamon, Prof. Dr. M. Yamaguchi (Kyoto Universtiy, Japan)

Veröffentlichungen:

Salamon, M., K. Ito, M. Yamaguchi, K. Freitag, H. Mehrer: Diffusion of ⁷¹Ge in molybdenum disilicide, Mat. Sci. Forum, in print