Preparation and microstructures of BaTi1−xZrxO3 hetero-epitaxial thin films on SrTiO3 substrates

Abstract

Zr-substituted BaTiO3 thin films (BaTi1−xZrxO3: BTZ) were prepared by rf-sputtering on SrTiO3 (STO) substrates or STO substrates buffered by pulsed laser deposited SrRuO3 (SRO) electrodes. The epitaxial growth of BTZ was monitored in situ by reflective high energy electron diffraction. X-ray reflectivity measurement demonstrated that a smooth surface with a roughness of 0.5 nm could be achieved under optimized deposition parameters. Film composition and the change in chemical environment due to Zr substitution are discussed based on electron energy-loss spectroscopy. The high quality of the interfaces was confirmed by transmission electron microscopy. The epitaxial relation between BTZ/SRO and SRO/STO was studied by selected area diffraction and high resolution transmission electron microscopy. All the results show that high quality epitaxial BTZ thin films were successfully deposited and ready for further electrical studies.