18O oxygen tracer diffusion coefficients and activation energies were determined in polycrystalline lead lanthanum zirconate titanate with varying La concentrations in the temperature range of 500 to 800C. For this purpose the isotope exchange method and secondary ion mass spectrometry depth profiling were used. As a novel approach a chemically reduced sample was prepared by annealing at low oxygen partial pressure (p (O2) ≈ 10–13Pa). Subsequently the sample was thermally charged with 18O as well. Results indicated a higher diffusion rate in the reduced sample than in as-received lead lanthanum zirconate titanate thus leading to the assumption that the diffusion mechanism in the material was vacancy-driven despite the strong donor doping of the perovskite lattice.

18Oxygen Diffusion in Polycrystalline Lead Lanthanum Zirconate Titanate. S.Hummelt, S.Flege, W.Ensinger: Physica Status Solidi Rapid Research Letters, 2010, 4[8-9], 203–5