Impurity diffusion in icosahedral Al-Mn

Abstract

The platinum-impurity diffusion in icosahedral ${\mathrm{Al}}_{86}$${\mathrm{Mn}}_{14}$ produced by melt spinning has been measured for the first time. Platinum was introduced into the metastable Al alloy by ion implantation, and depth profiles were measured by Rutherford-backscattering spectrometry. The activation energy for diffusion is found to be 1.1 eV. The preexponential factor is evaluated to be 3\ifmmode\times\else\texttimes\fi{}${10}^{11}$ ${\mathrm{m}}^{2}$/s, a value which is about six orders of magnitude smaller than that observed for normal diffusion in Al.