Effect of bottom electrode on the microstructure and electrical properties of sputtered BaTiO3 films on MgO substrates

• Epitaxial BaTiO3/(La0.5Sr0.5)CoO3 heterostructures were successfully grown on MgO.
• BaTiO3’s preferred orientation on Pt/MgO was dependent on the texture of Pt.
• Pt’s texture on MgO was engineered by tuning its growth temperature.
• Electrical properties of BaTiO3/Pt were compared with those of BaTiO3/LSCO on MgO.

Conductive (La0.5Sr0.5)CoO3 and Pt layers were prepared on (1 0 0) MgO substrate respectively as bottom electrode for BaTiO3 films. While the (La0.5Sr0.5)CoO3 layer showed a cube-on-cube epitaxy on MgO, thus promoting the heteroepitaxial growth of the successively grown BaTiO3 film, the Pt layer was polycrystalline with a texture highly dependent on the growth temperature. BaTiO3 films of the same thickness (∼320 nm) deposited on (La0.5Sr0.5)CoO3 and Pt layers with different textures were comparatively investigated. The differences in electrical properties are found to be closely related to the crystalline orientation and interface states of the BaTiO3 films on different bottom electrode layers.