Bilayered BiFe0.95Mn0.05O3/Bi0.90La0.10FeO3 Thin Films with Low Ferroelectric Coercivity and Large Remanent Polarization

Bilayered thin films consisting of (Bi0.90La0.10)FeO3 and Bi(Fe0.95Mn0.05)O-3, i.e., Bi(Fe0.95Mn0.05)O-3/(Bi0.90La0.10)FeO3, were deposited on SrRuO3 buffered SrTiO3(111) substrates by off-axis radio frequency magnetic sputtering, where (111)-oriented bilayered thin films were obtained. The bilayered Bi(Fe0.95Mn0.05)O-3/(Bi0.90La0.10)FeO3 thin film possesses a lower coercive field (2E(c)similar to 335.6 kV/cm) and a larger remanent polarization (2P(r)similar to 155.2 mu C/cm2) at room temperature, and a higher relative permittivity as compared with those of single-layer (Bi0.90La0.10)FeO3 and Bi(Fe0.95Mn0.05)O-3 thin films, together with an improvement of the magnetic properties (2M(s)similar to 31.2 emu/cm3). The bottom (Bi0.90La0.10)FeO3 nanolayer promotes the growth of the Bi(Fe0.95Mn0.05)O-3 layer, which are largely responsible for the multiferroic behavior observed.