Microstructure of Ba0.5Sr0.5TiO3 thin films on (100)LaAlO3 with SrRuO3 as electrodes

摘要

Using pulsed-laser deposition, we grew quaternary Ba0.5Sr0.5TiO3 thin films heteroepitaxially on (100) LaAlO3 substrates with conductive SrRuO3 as a bottom electrode. The microstructure of this multilayer of Ba0.5Sr0.5TiO3/SrRuO3/LaAlO3, was characterized by X-ray diffraction and cross-sectional transmission electron microscopy. The heteroepitaxial growth relationship was found to be (h00)(Ba0.5Sr0.5TiO3)parallel to(00l)(SrRuO3)parallel to(h00)(LaAlO3) and [110](Ba0.5Sr0.5TiO3)parallel to [100](SrRuO3)parallel to[110](LaAlO3). The high dielectric constant of the crystalline Ba0.5Sr0.5TiO3 thin films and the low leakage current of the Ba0.5Sr0.5TiO3 film sandwiched between a top Au and bottom SrRuO3 electrodes are attributed to the structural perfection of the films and the clean interfaces between layers.