Lead-free (1−x)Bi_0.5Na_0.5TiO₃–x(Sr_0.7Bi_0.2□_0.1)TiO₃ (x = 0.0, 0.1, 0.2 and 0.3, denoted as BNT–xSBT) thin films were deposited on Pt(111)/Ti/SiO₂/Si substrates by the sol–gel method, and their microstructure and dielectric, ferroelectric and piezoelectric properties were investigated in detail. All thin films present a single perovskite structure as demonstrated. In particular, appropriate Mn doping modifies the concentration of oxygen vacancies in thin films, resulting in a marked decline in leakage current. In this way, an ultra-high inverse piezoelectric coefficient (d₃₃* ∼144.11 pm V⁻¹) can be obtained from a 0.8BNT–0.2SBT thin film, and a maximum polarization P_m of 46.88 μC cm⁻² is observed under an electric field of 700 kV cm⁻¹. Meanwhile, a BNT–SBT thin film has flexible dielectric tunability. All results strongly suggest that the ultra-high piezoelectric property of BNT–0.2SBT is derived from the ferroelectric-to-relaxor transition. As described, this work indicates that the BNT–SBT thin film is an ideal lead-free piezoelectric substituted material. Moreover, BNT–SBT is a novel system of thin films, which has a great development prospect.

中文翻译：

---

新型（1-x）Bi0.5Na0.5TiO3-x（Sr0.7Bi0.2□0.1）TiO3薄膜的增强压电性和降低的漏电流

在Pt上沉积无铅（1- x）Bi _0.5 Na _0.5 TiO ₃ - x（Sr _0.7 Bi _0.2 □ _0.1）TiO ₃（x = 0.0、0.1、0.2和0.3，分别表示为BNT– x SBT）薄膜（111）/ Ti / SiO ₂溶胶-凝胶法制备/ Si衬底，并对其微观结构，介电，铁电和压电性能进行了详细研究。如图所示，所有薄膜均呈现单一钙钛矿结构。特别地，适当的Mn掺杂改变了薄膜中氧空位的浓度，导致漏电流的显着下降。这样，可以从0.8BNT-0.2SBT薄膜获得超高的逆压电系数（d ₃₃ *〜144.11 pm V ^-1），并且在以下条件下观察到最大极化P _m为46.88μCcm ^-2。 700 kV cm ^-1的电场。同时，BNT-SBT薄膜具有灵活的介电可调性。所有结果都强烈表明，BNT–0.2SBT的超高压电特性源自铁电至弛豫转变。如上所述，这项工作表明BNT-SBT薄膜是理想的无铅压电替代材料。而且，BNT-SBT是一种新型的薄膜体系，具有广阔的发展前景。