The tracer diffusivity of these metals in polycrystalline samples was studied at temperatures of between 600 and 950C, under an O partial pressure of 1atm, by using serial sectioning or secondary ion mass spectrometry methods (figure 2). It was found that the present results (tables 57 and 58) fell upon the same Arrhenius curve 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. The diffusion coefficients for Zn and Cu, and the published values for Ni, were close to each other. The activation energies were almost the same (table 59). 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. The diffusivity of Cu was lower than that of Ag, and this was tentatively attributed to an attraction of Ag for O-ion vacancies. It was also suggested that an interaction between cations and O vacancies could explain an increase in the diffusivity of Cu, with decreasing O partial pressure, at 850C (table 60).

J.L.Routbort, S.J.Rothman, N.Chen, J.N.Mundy, J.E.Baker: Physical Review B, 1991, 43[7], 5489-97

Table 57

Diffusion of 65Zn in Polycrystalline Cu3Ba2YO7

Table 58

Diffusion of Co in Cu3Ba2YO7

Table 59

Diffusion Parameters for Bulk Cu3Ba2YO7

Table 60

Diffusion of 64Cu in Polycrystalline Cu3Ba2YO7

Figure 2

Diffusivity of Co in Cu3Ba2YO7