Characterization of epitaxial thin films of Bi_2VO_(5.5) on La-doped SrTiO_3 substrates prepared by coating-pyrolysis process

摘要

Epitaxial thin films of Bi_2VO_(5.5) (BVO) were prepared on La-doped SrTiO_3 (LSTO) by a coating-pyrolysis process. The BVO films were (001)- and (114)-oriented on LSTO(100) and (110), respectively. Atomic force microscopic observations showed that very dense surfaces were obtained in the BVO films annealed at 600℃ and p_(O_2) = 10~(-4) atm. The step heights of the BVO(001) film were in the range of 2-12 nm, each approximately corresponding to a multiple of the c-axis parameter of BVO. The low-p_(O_2)-processed and O_2-postannealed BVO films resulted in reproducible P-E hysteresis loops for both orientations, although somewhat leaky characteristics were observed at higher applied voltages. Anisotropic behavior based on the orientation difference was clearly observed.