Surface double-layer structure in (110) oriented BiFeO3 thin film.

Surface double-layer structure different from the interior was found in BiFeO₃ thin film grown on SrRuO₃ covered SrTiO₃ (110) substrate by pulsed laser deposition. It was shown that BiFeO₃ film exhibits epitaxial phase with single domain. X-ray reflectivity and X-ray photoelectron spectroscopy results revealed a skin layer of less than 1 nm with a reduced electron density and different surface state. Grazing incidence x-ray diffraction convinced a surface multi-domain structure of several nm beneath the surface skin layer. The double-layer near surface structure would be originated from the large depolarization field produced by the single-domain structure with strain. [ABSTRACT FROM AUTHOR]