Diffusion in the intermetallic Laves-phase Co₂Nb

Self-diffusion of both constituents in the Laves-phase NbCo₂ has been explored using the tracer method. The temperature dependences of the Co diffusivity in Nb₃₁Co₆₉ and Nb₂₉Co₇₁ and of the Nb diffusivity in Nb₃₁Co₆₉ have been studied. All activation enthalpies are of similar magnitude. Nb diffusion in NbCo₂ is significantly slower than Co diffusion. Co diffusion itself is considerably faster in the alloy with higher Co content. The diffusion results are discussed in connection with the structure and the information available about atomic defects in NbCo₂. We propose that diffusion is mediated by thermal vacancies.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Dr. M. Denkinger (bis März 1999), Prof. Dr. H. Mehrer (Leiter)

Veröffentlichungen:

Denkinger, M., H. Mehrer: Self-diffusion of both components in the intermetallic Laves-phase NbCo₂, Mat. Res. Soc. Symp. Proc. Vol. 552, 471 - 476, 1999.

Denkinger, M., H. Mehrer: Diffusion in the C15-type intermetallic Laves-phase Co₂Nb, Phil. Mag. A 80, 1245 - 1263 (2000)

Dissertation: Martin Denkinger: "Grundlagen der Festkörperdiffusion und Selbstdiffusion in der kubischen Laves-phase NbCo₂" (1999)