The diffusion of O in undoped and Ag-doped single crystals was investigated by performing isothermal resistivity measurements at temperatures ranging from 550 to 750C. It was found that the diffusion coefficients for Ag-doped crystals were an order of magnitude lower than those for undoped ones (table 80). Furthermore, the activation energy for O diffusion was found to be considerably higher for Ag-doped crystals. Further analysis of the data indicated that doping with Ag stabilized the phase at higher O contents.

D.K.Aswal, S.K.Gupta, P.K.Mishra, V.C.Sahni: Superconductor Science and Technology, 1998, 11[7], 631-6