The rhombic triacontahedral-type icosahedral quasicrystal, and its 1/1 and 2/1 approximants, in Al-Mg-Zn alloys were systematically studied by means of positron annihilation measurements. The structural vacancy densities, average positron diffusion lengths, average positron diffusion lengths in the vacancy-free region, positron diffusion coefficients and positron mobilities were successfully derived. The results indicated that thermalized positrons in the vacancy-free regions tended to localize as the order of the approximant increased.

Positron-Trapping Property in Al–Mg–Zn Alloy System. K.Sato, H.Uchiyama, I.Kanazawa, E.Hamada, T.Suzuki, T.Takeuchi, U.Mizutani: Journal of Alloys and Compounds, 2002, 342[1-2], 306-9