Effects of substrate temperature on the physical properties of strained BaTiO3/LaNiO3 artificial superlattices

An artificially layered perovskite composed of dielectric BaTiO3 (BTO) and conductive LaNiO3 (LNO) was grown on a LaNiO3-coated SrTiO3 (0 0 1) single crystal substrate by a radio-frequency magnetron sputtering system. The cross-sectional image of transmission electron microscopy confirmed the formation of BTO/LNO superlattice structure. Moreover, the clearly main feature and satellite features from the (0 0 L) Bragg reflection of X-ray indicate the high quality of the BTO/LNO superlattice structure was formed on a LaNiO3-coated SrTiO3 substrate. All the superlatttice films deposited at 300-550 °C show a significant enhancement of dielectric constant relative to the BTO single epilayer of the same effective thickness; the higher is the deposition temperature, the larger is the dielectric constant of the films present.