The tracer diffusivity of Ni in polycrystalline samples was studied at between 600 and 950C, under an O partial pressure of 1atm, by using serial sectioning or secondary ion mass spectrometry methods. It was found that the present results fell upon the same Arrhenius curve,

D (cm2/s) = 2 x 100 exp[-247(kJ/mol)/RT]

as did previous data. The diffusivity of Ni in monocrystalline material was equal to 1.9 x 10-15 cm2/s at 700C and equal to 1.3 x 10-16cm2/s at 600C. Measurements of Co and Ni diffusion in the c-axis direction of monocrystalline platelets indicated that there was a much greater diffusional anisotropy in the case of Co.

Site Selectivity and Cation Diffusion in YBa2Cu3O7-δ. J.L.Routbort, S.J.Rothman, N.Chen, J.N.Mundy, J.E.Baker: Physical Review B, 1991, 43[7], 5489-97

Figure 23

Diffusivity of Co in Cu3Ba2YO7