Control of epitaxial growth for SrBi2Ta2O9 thin films

Abstract

We report the (a00) oriented as well as the (00l) oriented epitaxial SrBi2Ta2O9 thin film grown on (100) LaAlO3 and (200) yttria-stabilized zirconia single crystal substrates. On (100) SrTiO3 single crystal substrate, we only observe the (00l) oriented epitaxial growth of SrBi2Ta2O9 thin film. We infer that the (a00) oriented epitaxial growth results from the strain by the lattice mismatch. The band gaps of the (00l) and the (a00) oriented SrBi2Ta2O9 films are ∼3.9 and ∼3.5 eV, respectively. The two epitaxial orientations of ferroelectric SrBi2Ta2O9 thin film can provide an opportunity to study the effects on microwave and optical waveguides as well as underlying anisotropic physical properties.