Self-diffusion of manganese in AlPdMn icosahedral quasicrystals

Abstract Self-diffusion of 54 Mn in Al 72 Pd 20 Mn 8 icosahedral quasi-crystals has been investigated over the temperature range from 723 to 1022 K. Concentration depth profiles of the radioisotope 54 Mn in the AlPdMn quasi-crystal and Al 60 Pd 25 Mn 15 crystal have been measured by an ion-beam sputter-sectioning technique. The temperature dependence of the self-diffusivity of Mn in Al 72 Pd 20 Mn 8 icosahedral quasicrystals is expressed as D =(1.1 0.5 1.0 )×10 −10 exp(−134.0±4.5kJ mol −1 / RT )m 2 s −1 The self-diffusivity of Mn in Al 72 Pd 20 Mn 8 icosahedral quasicrystals is about two orders of magnitude smaller than that in Al 60 Pd 25 Mn 15 crystalline alloy. The self-diffusivity of Mn in the quasi-crystal is also three to four orders of magnitude lower than Mn diffusivity in crystalline Al.