Abstract The Bi0.92-xHo0.08AxFe0.97Mn0.03O3/Zn0.5Ni0.5Fe2O4 (BHAFMO/ZNFO, A=Ca, Sr and Ba) bilayered thin films were deposited on FTO/glass substrates by using the chemical solution deposition method. The structure, leakage current and multiferroic properties were investigated. The results indicate that the increase of oxygen vacancies in the BHAFMO/ZNFO films lead to the increase of Schottky barrier, which is beneficial to the bulk limiting conduction mechanism (Ohmic and space-charge-limited-conduction (SCLC)). But the increase of Schottky barrier also leads to the polarization relaxation of BHAFMO/ZNFO films, and domain switching is more difficult. These indicate that the concentration and migration of oxygen vacancies can be controlled by ions doped BHFMO/ZNFO films with different ionic radii. Adjustment of the interface barrier and Schottky barrier by controlling the oxygen vacancies could not only change the conduction mechanism, but also adjust the ferroelectric domain switching to influence ferroelectric polarization. Because the structure is close to the morphotropic phase boundary (MPB), the substitutional ionic radius is larger than that of Bi3+, and the concentration of oxygen vacancies is low, so the BHSrFMO/ZNFO film exhibits excellent ferroelectric properties (the remnant polarization (Pr) = 82.1 μC/cm2 and the coercive field (Ec) = 566 kV/cm).

中文翻译：

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通过可调肖特基势垒和界面势垒增强 Bi 0.92 Ho 0.08 Fe 0.97 Mn 0.03 O 3 /Zn 0.5 Ni 0.5 Fe 2 O 4 双层薄膜的多铁性

摘要 采用化学溶液沉积法在FTO/玻璃基板上沉积Bi0.92-xHo0.08AxFe0.97Mn0.03O3/Zn0.5Ni0.5Fe2O4（BHAFMO/ZNFO，A=Ca、Sr和Ba）双层薄膜。研究了结构、漏电流和多铁性。结果表明，BHAFMO/ZNFO薄膜中氧空位的增加导致肖特基势垒的增加，这有利于体限制传导机制（欧姆和空间电荷限制传导（SCLC））。但是肖特基势垒的增加也会导致 BHAFMO/ZNFO 薄膜的极化弛豫，畴切换更加困难。这些表明氧空位的浓度和迁移可以通过具有不同离子半径的离子掺杂 BHFMO/ZNFO 薄膜来控制。通过控制氧空位来调节界面势垒和肖特基势垒不仅可以改变导电机制，还可以调节铁电畴的切换来影响铁电极化。由于结构接近同形相界（MPB），置换离子半径比Bi3+大，氧空位浓度低，所以BHSrFMO/ZNFO薄膜表现出优异的铁电性能（剩余极化（Pr ) = 82.1 μC/cm2 和矫顽场 (Ec) = 566 kV/cm）。