The tracer diffusion of 18O in polycrystalline Hg0.75Re0.25Ba2Ca2Cu3Ox was measured at 450C. The concentration profiles, measured by the secondary-ion mass spectrometry of 18O, included a region beneath the surface that could be fitted to a solution of the diffusion equation in order to deduce the volume diffusion coefficient. They also featured a long tail that did not decrease to the expected background concentration of 18O. The calculated diffusion coefficient was between 2.6 x 10-15 and 2.3 x 10-14cm2/s.

Measurement of Oxygen Diffusion in Polycrystalline (Hg,Re)Ba2Ca2Cu3Ox. S.Tsukui, K.C.Goretta, J.L.Routbort, A.Sin: Physica C, 2002, 378-381[1], 701-6