Abstract
The anisotropy of the oxygen diffusion in the high-Tc-super con duc tor Bi2Sr2CaCu2O8 + 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 = τ0−1exp [ − 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 la te ral dimensions ∼ 1 μm.