Published online by Cambridge University Press: 10 February 2011
Self-diffusion of57Co and95Nb in the cubic Laves phase NbCo2 has been studied using the radiotracer method. The temperature dependences of the self-diffusivities are described for Nb31Co69 by
,
and for Nb29Co71 by
,
The diffusivity of 95Nb in Nb31Co69 is considerably lower than that of 57Co. The latter increases significantly with increasing Co content.
The results are discussed in terms of vacancy mediated diffusion in connection with structural aspects of the Laves phase together with the scarce information available for defects in NbCo2. The results are compared with interdiffusion data from our laboratory and with self-diffusion in the also close-packed L12 intermetallics.