Microstructure and ferroelectric properties of BaTiO3 films on LaNiO3 buffer layers by rf sputtering

We have fabricated LaNiO3 and BaTiO3 films using the rf sputtering method. The LaNiO3 were deposited on Si substrates, demonstrating a (1 0 0) highly oriented structure and nanocrystalline characteristic with a grain size of 30 nm. The BaTiO3 thin films were deposited on the LaNiO3 buffer layers, and have exhibited a (1 0 0) texture with a thickness of 400 nm. A smooth interface is obtained between the LaNiO3 bottom electrode and the BaTiO3 film from cross-section observations by scanning electron microscopy. The bi-layer films show a dense and column microstructure with a grain size of 60 nm. Ferroelectric characterizations have been obtained for the BaTiO3 films. The remnant polarization and coercive field are 2.1 μC/cm2 and 45 kV/cm, respectively. The leak current measurements have shown a good insulating property.