The effect of proton bombardment upon the diffusion of implanted 103Pd or 195Au in icosahedral Al70.2Pd21.3Mn8.5 was investigated. Following implantation, the specimens were diffusion-annealed under simultaneous 0.5 or 1MeV proton bombardment. Serial sectioning was performed by using precision grinding or Ar+-beam sputtering; depending upon whether the mean diffusion depth was equal to 10 to 100μm, or to some hundreds of nm. The results were in accord with the suggestion that, in the absence of bombardment, diffusion in the high-diffusivity regime (greater than 10-18m2/s) was mediated by thermal vacancies. For diffusivities below about 10-18m2/s, diffusion occurred via a direct interstitial mechanism which involved collective phason flips.

Diffusion of 103Pd and 195Au in Icosahedral Al70.2Pd21.3Mn8.5 under Proton Irradiation. R.Blüher, W.Frank, B.Grushko: Materials Science and Engineering A, 2000, 294-296, 689-92