Growth and characterization of (001)-oriented Pb(Zr0.52Ti0.48)O3/LaNiO3/LaAlO3 heterostructures prepared by pulsed laser deposition

Completely (001)-oriented ferroelectric Pb(Zr0.52Ti0.48) O-3/ LaNiO3 heterostructures on single-crystal LaAlO3( 001) substrates have been successfully grown by pulsed laser deposition. X-ray-diffraction analyses (theta- 2 theta scan, omega scan and phi scan) indicate that good out-of-plane orientation and in-plane alignment have been obtained with the epitaxial relationship of PZT(001)//LNO(001)// LAO( 001) and PZT [001]// LNO [001]// LAO [001]. Scanning electron and atomic force microscopic images reveal very smooth LNO surfaces with roughness of about 0.4 - 0.6 nm. Based on a microstructural study of the LNO and PZT films, a layer-by-layer growth mode for the LNO growth is proposed, while island growth is dominant for the PZT films. Secondary ion mass spectroscopy analyses show that no distinct interdiffusion can be found between the PZT and LNO layers. P - E hysteresis loop measurements of the PZT films with LNO as bottom electrodes and Au as top electrodes were carried out at an applied voltage of 5 V. The best remanent polarization Pr and coercive field E-c were found to be 28 mu C/cm(2) and 74.5 kV/cm, respectively.