Effects of substrate temperature on the physical properties of strained BaTiO_3/LaNiO_3 artificial superlattices

摘要

An artificially layered perovskite composed of dielectric BaTiO_3 (BTO) and conductive LaNiO_3 (LNO) was grown on a LaNiO_3-coated SrTiO_3 (001) 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 (00 L) Bragg reflection of X-ray indicate the high quality of the BTO/LNO superlattice structure was formed on a LaNiO_3-coated SrTiO_3 substrate. All the superlatttice films deposited at 300-550℃ 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.