Epitaxial growth of SrBi₂Nb₂O₉ on (110) SrTiO₃ and the establishment of a lower bound on the spontaneous polarization of SrBi₂Nb₂O₉

Epitaxial SrBi₂Nb₂O₉ thin films have been grown on (110) SrTiO₃ substrates by pulsed laser deposition. Four-circle x-ray diffraction and transmission electron microscopy reveal nearly phase pure epitaxial films with the c axis of the films at 45° with respect to the substrate normal. Electrical characterization is presented for films grown on epitaxial SrRuO₃ electrodes. The low-field relative permittivity was 235, the remanent polarization was 11.4 μC/cm², and the dielectric loss was 3.0% for 0.3-μm-thick films. From the remanent polarization and an understanding of the epitaxial geometry, a lower bound of 22.8 μC/cm² was determined for the spontaneous polarization of SrBi₂Nb₂O₉.