Oxygen isotope exchange experiments are performed in donor doped PbZrxTi1-xO3 (PZT) under field load. A detailed mapping of the oxygen tracer ions and thus indirectly of the oxygen vacancy distribution is enabled by spatially resolved time-of-flight secondary ion mass spectrometry (ToF-SIMS). Hence, knowledge can be gained on the oxygen vacancy redistribution under the influence of high electric fields applied to Cu inner electrodes of a PZT multilayer stack. Upon field load an enhanced oxygen tracer concentration is measured near to the cathode and interpreted in terms of a field-driven oxygen vacancy accumulation at an oxide ion blocking Cu cathode. Oxygen tracer depth profiles in near-anode and near-cathode diffusion zones give quantitative information on local grain and grain boundary diffusion coefficients and their dependence on applied voltages. (C) 2013 Elsevier B.V. All rights reserved.