Bilayered BiFe_(0.95)Mn_(0.05)O_3/Bi_(0.90)La_(0.10)FeO_3 Thin Films with Low Ferroelectric Coercivity and Large Remanent Polarization

摘要

Bilayered thin films consisting of (Bi_(0.90)La_(0.10))FeO_3 and Bi(Fe_(0.95) Mn_(0.05))O_3, I.e., Bi(Fe_(0.95)Mn_(0.05))O_3/(Bi_(0.90)La_(0.10))FeO_3, were deposited on SrRuO_3 buffered SrTiO_3(111) substrates by off-axis radio frequency magnetic sputtering, where (111)-oriented bilayered thin films were obtained. The bilayered Bi(Fe_(0.95) Mn_(0.05))O_3/(Bi_(0.90)La_(0.10))FeO_3 thin film possesses a lower coercive field (2E_c ～ 335.6 kV/cm) and a larger remanent polarization (2P_r～ 155.2 μC/cm~2) at room temperature, and a higher relative permittivity as compared with those of single-layer (Bi_(0.90)La_(0.10))FeO_3 and Bi(Fe_(0.95)Mn_(0.05))O_3 thin films, together with an improvement of the magnetic properties (2M_s～31.2 emu/cm~3). The bottom (Bi_(0.90)La_(0.10))FeO_3 nanolay-er promotes the growth of the Bi(Fe_(0.95)Mn_(0.05))O_3 layer, which are largely responsible for the multiferroic behavior observed.