The diffusion of Ag in superconducting YBa2Cu3O7 ceramic was studied (700 to 850C, 5 to 24h) by using the energy-dispersive X-ray fluorescence technique. For the excitation of Ag atoms, an annular 241Am radioisotope source (50mCi) emitting 59.543keV photons was used. The temperature dependences of Ag diffusivities in grains (D1) and grain boundaries at 700 to 850C (D2) were described by:

D1 = 1.4 x 10-2 exp[-1.18/kT]

D2 = 3.1 x 10-4 exp[-0.87/kT]

However, it was noted that the diffusion data depended upon the length of time at the annealing temperature (table 6).

The Effect of Duration of Diffusion on Ag Diffusion Coefficients in YBa2Cu3O7. O.Dogan: Journal of Quantitative Spectroscopy and Radiative Transfer, 2005, 95[2], 263-9