The diffusion coefficients of impurities in bulk glasses having various Be/Ti ratios were measured, at temperatures near to the glass transition, by using secondary ion mass spectrometry. During long-term annealing, a Zr41Ni30Be22.5Ti14Cu12.5 glass underwent amorphous decomposition and the diffusion coefficients decreased by more than an order of magnitude. Two glasses, Zr41Ni10Be27.8Ti8.7Cu12.5 and Zr41Ni10Be20Ti16.5Cu12.5, which were prepared in order to represent the decomposition phases of the first glass, also exhibited a tendency to decomposition and time-dependent diffusion coefficients. Diffusion measurements which were performed during short-term annealing yielded only small differences between the temperature dependences of the diffusion coefficients of various impurities in all of the alloys. It was found that, in general, the size rule was obeyed. That is, the activation energies for diffusion increased with increasing atomic size. The Arrhenius curves were non-linear; thus indicating a significantly higher activation energy above about 580K, than below. No systematic effect of the glass composition upon diffusion was observed.

Dependence of Diffusion on the Alloy Composition in ZrTiCuNiBe Bulk Glasses. M.P.Macht, V.Naundorf, P.Fielitz, J.Rusing, T.Zumkley, G.Frohberg: Materials Science and Engineering A, 2001, 304-306, 646-9