Diffusion in icosahedral Al–Pd–Mn quasicrystals: temperature and pressure dependence

The temperature and pressure dependence of diffusion in monocrystalline icosahedral Al–Pd–Mn quasicrystals (i-Al–Pd–Mn) was investigated by radiotracer techniques using serial sectioning for depth profiling. Recent results on the temperature dependence of 65Zn, 114mIn and 103Pd diffusion are presented together with previous ones on 54Mn and 59Fe diffusion from our laboratory. The temperature dependence of diffusion is discussed in connection with results on i-Al–Pd–Mn from other groups and compared with the diffusion of foreign elements in Al. This comparison suggests a vacancy mechanism for diffusion in i-Al–Pd–Mn at least at higher temperatures. Magnitude and sign of the activation volumes also support a vacancy mechanism.