Mn4+:BiFeO3/Zn2+:BiFeO3 bilayered thin films of (1 1 1) orientation

Ferroelectric and fatigue behavior of bilayered thin films consisting of Mn4+-modified BiFeO3 and Zn2+-modified BiFeO3, which were deposited on SrRuO3-buffered Pt coated silicon substrates, were systematically investigated. The (1 1 1) orientation is induced for the BiFe0.95Mn0.05O3/BiFe0.95Zn0.05O3 bilayer, due to the introduction of the bottom BiFe0.95Zn0.05O3 layer. With increasing the thickness ratio of the BiFe0.95Mn0.05O3 layer, their leakage current decreases, and the fatigue endurance is greatly improved owing to the introduction of the BiFe0.95Mn0.05O3 layer with a lower fatigue rate. The BiFe0.95Mn0.05O3/BiFe0.95Zn0.05O3 bilayer with the thickness ratio of 3:1 exhibits a larger remanent polarization of 2Pr ∼ 161.0 μC/cm2 than those of bilayers with different thickness ratios, while their coercive field slightly increases with increasing the thickness ratio of the BiFe0.95Mn0.05O3 layer.