The orientational dependence of 60Co self-diffusion was investigated in stable decagonal single quasicrystals by using radiotracer methods. At 803 to 1210K, the temperature dependences of the Co diffusivities along the periodic (10-fold axis) and the aperiodic (2-fold axis) directions could be described by a single set of Arrhenius parameters. The temperature dependence of the diffusion coefficients yielded the relationships:

periodic:     D (m2/s) = 1.54 x 10-1 exp[-277.4(kJ/mol)/RT]

aperiodic:     D (m2/s) = 3.96 x 10-1 exp[-289.0(kJ/mol)/RT]

The mobility of Co was slightly greater along the periodic direction. This anisotropic effect was explained in terms of the results of analogous diffusion investigations of icosahedral quasicrystals.

T.Zumkley, H.Nakajima, J.Q.Guo, A.P.Tsai: Philosophical Magazine A, 2002, 82[1], 205-13