Polarization switching and fatigue in Pb(Zr0.52Ti0.48)O3 films sandwiched by oxide electrodes with different carrier types

By using highly conductive p-type La0.7Sr0.3MnO3 (LSMO) and n-type La0.07Sr0.93SnO3 (LSSO) as electrodes, all-oxide Pb(Zr0.52Ti0.48)O-3 (PZT) capacitors, LSMO/PZT/LSMO, LSSO/PZT/LSSO, LSSO/PZT/LSMO, and LSMO/PZT/LSSO, have been grown epitaxially on (001)SrTiO3 substrates, and their structure, switching, fatigue, and optical properties were investigated. Strikingly, contrary to the LSMO/PZT/LSMO capacitors, those having the n-type electrode show poor fatigue resistance especially at lower driving frequencies, which was further confirmed by using another n-type oxide electrode, SrTi0.9Sb0.1O3. The results suggest that with a depletion layer at the PZT/LSSO interface, charge accumulation and injection during switching may be responsible for the fatigue. (C) 2007 American Institute of Physics.