Hydrogen interstitial defects in acceptor-type CuO-doped PbTiO3—Uptake and dissolution of water vapor and formation of (CuTi″−(OH)O•)′ defect complexes

Abstract

The defect structure of CuO-doped PbTiO3 has been analyzed using the Hyperfine Sublevel Correlation Experiment to identify hydrogen interstitials. The formation of (CuTi″−(OH)O•)′ defect complexes has been observed, which exist in addition to the (CuTi″−VO••)× complexes. On this basis, modified reorientation characteristics are proposed due to a change in hopping mechanism from an oxygen-vacancy mediated migration mechanism to a proton hopping process. Furthermore, mobile hydrogen interstitials are generated that increase conductivity in terms of a “Grotthuss”-type charge-transport mechanism.