Mn Self-Diffusion in Single Grain Icosahedral Al70Pd21.5Mn8.5 Quasicrystals.

The self-diffusivity of {sup 54}Mn in single grain icosahedral Al{sub 70}Pd{sub 21.5}Mn{sub 8.5} quasicrystals has been determined by a precision grinding technique. In the range from 870 to 1093K the temperature dependence of the Mn self-diffusivity {ital D} follows the Arrhenius equation with an activation energy {ital Q}=(180.8{plus_minus}4.5) kJmol{sup {minus}1} and a preexponential factor {ital D}{sub 0}=3.4{times}10{sup {minus}4} m{sup 2}s{sup {minus}1}. The experimental results are discussed together with diffusion mechanisms proposed for quasicrystals from theoretical considerations. {copyright} {ital 1996 The American Physical Society.}