Interfacial origin of enhanced energy density in SrTiO 3-based nanocomposite films

摘要

AbstractSrTiO3-based films doped with different Al-precursors were prepared by sol-gel methods and the dielectric strengths and leakage currents of the materials were investigated. The best performance was found in SrTiO3films doped with Al2O3nanoparticles (nano-Al2O3). When 5mol% of nano-Al2O3was added to SrTiO3films with Al electrodes, the dielectric strength was enhanced to 506.9MV/m compared with a value of 233.5MV/m for SrTiO3films. The energy density of the 5mol% nano-Al2O3doped SrTiO3films was 19.3J/cm3, which was also far higher than that of the SrTiO3films (3.2J/cm3). These results were attributed to interfacial anodic oxidation reactions, which were experimentally confirmed by cross-sectional transmission electron microscope studies and theoretically modelled based on Faraday's laws. The films with added nano-Al2O3featured many conducting paths at the interfaces between the host phase and the guest nano-Al2O3, which promoted ion transport and contributed to the strong anodic oxidation reaction capability of the 5mol% nano-Al2O3doped SrTiO3films.]]>