The anisotropy of the oxygen diffusion in the high-Tc-superconductor Bi2Sr2CaCu2O 8+δ was investigated using off-c-axis prepared thin films. High-quality oriented films with thickness 1000 Å and c-axis inclined by a tilt angle α with respect to the normal of the film surface were grown up to α = 15 • . Oxygen diffusion following a small change of the ambient oxygen partial pressure in the temperature range 200-400 • C was monitored by in situ resistance measurements. Diffusion times according to an activated process τ −1 = τ −1 0 exp[−E/kBT ] were found, with E = 0.6 eV and τ0 = τ0(α) becoming smaller with increasing tilt angle. A comparison of the experimental τ0(α) with a calculation of τ0 for an ideal monocrystalline film suggests that as-grown films consist of crystalline grains with lateral dimensions ∼ 1 µm.

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