Electrode influence on the polarization properties of thin films prepared by off-axis laser deposition

and thin-film capacitors have been grown on (001) and MgO(001) substrates by off-axis laser deposition. Reflection high-energy electron diffraction (RHEED) and pole figures have revealed the epitaxial growth of the and thin films. The films with metal electrodes show only weak ferroelectric properties. Using as electrode material an essential improvement of the polarization behaviour could be achieved. heterostructures show a typical ferroelectric hysteresis loop with a remanent polarization of and a coercive field of about but with a relatively high leakage current density of about at an applied electrical field of . The improved polarization behaviour and the higher leakage current density of the all-perovskite structure is compared to those of the system. The differences are discussed on the basis of a Schottky-like depletion layer formation at the - electrode interface.