Isothermal annealing experiments were carried out on polycrystalline samples in air, at temperatures ranging from 300 to 900C. The O diffusion coefficients (figure 4) were determined by using a novel technique which involved the direct observation of O diffusion fronts by means of polarized light microscopy.

D.Shi, J.Krucpzak, M.Tang, N.Chen, R.Bhadra: Journal of Applied Physics, 1989, 66[9], 4325-8

Figure 4

Diffusivity of O in Cu3Ba2YO7