Evidence of highly collective Co diffusion in the whole stability range of Co-Zr glasses
Using a radiotracer technique, we have measured the isotope effect E = dln(D)/dln(m(1/2)) of Co diffusion in CoxZr1-x glasses for 0. 31</=x</=0.86. E is close to zero (E = 0+/-0.1) in the whole range, covering 3 orders of magnitude in the diffusivity, despite the existence of large activation volumes. These results strongly suggest a highly collective diffusion mechanism to be a quite general phenomenon in metallic glasses and point to diffusion via delocalized thermal effects at certain compositions.
Heesemann
A
Technische Fakultat der Christian-Albrechts-Universitat Kiel, Lehrstuhl fur Materialverbunde, Kaiserstrasse 2, D-24143 Kiel, Germany.
Zollmer
V
Ratzke
K
Faupel
F