Pb loss in Pb(Zr,Ti)O3 ceramics observed by in situ ionic conductivity measurements

Analysis of the impedance spectra of Nb-doped Pb(Zr,Ti)O-3 (PZT) embedded capacitors revealed that the ionic conductivity increased monotonically during annealing at 700 degrees C. Furthermore, the rate of increase was lowered by a reduction in the ambient pO(2). The results could be explained by a model in which oxygen vacancies are generated as a consequence of Pb evaporation from the PZT. At 700 degrees C, this process is most likely limited by surface kinetics rather than Pb bulk diffusion. It was shown that the Pb loss could be completely recovered by annealing in a high activity Pb source with a commensurate reduction in oxygen vacancy concentration. The electronic conductivity was predominantly p-type and was relatively unaffected by the Pb loss throughout the course of the, experiment. (C) 2011 American Institute of Physics. [doi:10.1063/1.3585831]