Preferential growth characteristics and ferroelectric properties of epitaxial SrBi2Nb2O9 thin films along the a-axis direction due to the misfit strains

Epitaxial SrBi2Nb2O9 (SBN) thin films were grown on single crystal (100) Nb-doped SrTiO3 (Nb:STO) substrates and (100) Rh substrates with different lattice constants, respectively. The Nb:STO substrates have a lattice constant similar to that of SBN and the epitaxial SBN thin films on the Nb:STO substrates were grown along the c-orientation, and the epitaxial SBN thin films on the Rh substrates were grown along a-orientation with a small lattice constant by compressive stress. The epitaxially a-oriented SBN thin films showed excellent ferroelectric properties compared to the epitaxially c-oriented SBN thin films because the SBN as a layered perovskite material has polar axis perpendicular to the c-orientation. It was confirmed that the epitaxially a-oriented SBN thin film having the polar axis parallel to the switching electric field has faster polarization switching speed than the epitaxially c-oriented SBN thin film having the polar axis perpendicular to the switching electric field. •Growth characteristics and ferroelectric properties.•Epitaxially c- and a- oriented SrBi2Nb2O9 thin films.•The stained induced by SrTiO3 and Rh substrates.