In this work, in order to optimize the electrical performance of (Na_0.85K_0.15)_0.5Bi_0.5TiO₃ (NKBT) thin films, 20 nm-thick BaTiO₃ (BTO) layer was utilized by deliberately coating in the NKBT film-substrate interface or in the NKBT film, i.e., BTO layers coated in sequence with NBKT layers. The BTO layer, especial coated in the NKBT film, was beneficial for crystallization process and more preferable to form a denser film morphology. The BTO-coated NKBT composite films exhibited much enhancement in electrical properties compared to the films without BTO layer. Accordingly, a high effective piezoelectric coefficient d₃₃^* of 75 pm/V and remnant polarization P_r of 22.1 μC/cm², as well as a low leakage current density of 1.2 × 10⁻⁵ A/cm² were obtained in the 460 nm-thick composite film with BTO layers coated in the NBKT film. It meant that this kind of BTO-coated NKBT composite film could perform as a potential candidate for the lead-free piezoelectric applications. The observed enhancement in the electrical properties with the introduction of BTO layer could be mainly explained by the weakened influence of domain pinning in the film-electrode interface and grain boundaries due to the decreased strain in the film-electrode interface and better crystallinity in the highly (110)-oriented NKBT films, thereby enhancing motion of domain-walls.

在这项工作中，为了优化（Na _0.85 K _0.15）_0.5 Bi _0.5 TiO ₃（NKBT）薄膜的电性能，通过在NKBT薄膜基板中故意涂覆20 nm厚的BaTiO ₃（BTO）层界面或在NKBT膜中，即BTO层依次涂有NBKT层。特别是在NKBT膜中涂覆的BTO层有利于结晶过程，更可取的是形成更致密的膜形态。与没有BTO层的薄膜相比，涂覆BTO的NKBT复合薄膜在电气性能方面表现出很大的提高。因此，高有效压电系数d ₃₃ ^*在460 nm厚的BTO涂层的复合薄膜中，获得了75 pm / V的磁通量和22.1μC/ cm ^2的剩余极化率_r，以及1.2×10 ^-5  A / cm ²的低漏电流密度。NBKT电影。这意味着这种BTO涂层的NKBT复合膜可以作为无铅压电应用的潜在候选者。引入BTO层后观察到的电学性能增强主要可以解释为由于膜电极界面的应变降低和高结晶度下结晶度的提高，膜电极界面和晶界的钉扎效应减弱了。 （110）取向的NKBT薄膜，从而增强了畴壁的运动。