Superconducting YBa2Cu3O7−x thin films were prepared on pure MgO and Ag/MgO substrates using an electron beam evaporation technique. Annealing of films on Ag/MgO substrates was accompanied by Ag diffusion from a buffer layer into YBCO films. The temperature dependence of the Ag diffusion coefficient in YBCO films at 600 to 800C was described by:

D(cm2/s) = 1.9 x 10-6 exp[-0.73(eV)/kT]

O.Görür, T.Küçükömeroğlu, C.Terzioğlu, A.Varilci, M.Altunbaş: Physica C, 2005, 418[1-2], 35-42