Measured S-parameters, as a function of positron incident energy, for the icosahedral quasicrystals Al71.5Pd20.3Mn8.2 and Al70.7Pd21.34Re7.96 were analyzed within the framework of the structural model of an approximant crystal. Highly resistive icosahedral quasicrystal Al72Pd21Re7 was investigated by using the slow positron beam technique. The results indicated that icosahedral quasicrystalline Al72Pd21Re7 contained a dense distribution of structural vacancy-type sites like other icosahedral quasicrystals. Relatively high structural vacancy densities (of the order of 1020/cm3) were determined.

Positron Diffusion in Icosahedral Quasicrystals. K.Sato, H.Uchiyama, I.Kanazawa, R.Tamura, K.Kimura, S.Takeuchi, T.Takeuchi, U.Mizutani: Applied Surface Science, 2002, 194[1-4], 155-9