Lead-free, silicon compatible materials showing large electromechanical responses comparable to, or better than conventional relaxor ferroelectrics, are desirable for various nanoelectromechanical devices and applications. Defect-engineered electrostriction has recently been gaining popularity to obtain enhanced electromechanical responses at sub 100 Hz frequencies. Here, we report record values of electrostrictive strain coefficients (M₃₁) at frequencies as large as 5 kHz (1.04×10⁻¹⁴ m²/V² at 1 kHz, and 3.87×10⁻¹⁵ m²/V² at 5 kHz) using A-site and oxygen-deficient barium titanate thin-films, epitaxially integrated onto Si. The effect is robust and retained upon cycling upto 6 million times. Our perovskite films are non-ferroelectric, exhibit a different symmetry compared to stoichiometric BaTiO₃ and are characterized by twin boundaries and nano polar-like regions. We show that the dielectric relaxation arising from the defect-induced features correlates well with the observed giant electrostriction-like response. These films show large coefficient of thermal expansion (2.36 × 10⁻⁵/K), which along with the giant M₃₁ implies a considerable increase in the lattice anharmonicity induced by the defects. Our work provides a crucial step forward towards formulating guidelines to engineer large electromechanical responses even at higher frequencies in lead-free thin films.

无铅、硅兼容材料显示出与传统弛豫铁电体相当或更好的大机电响应，对于各种纳米机电器件和应用来说是理想的。缺陷工程电致伸缩最近越来越受欢迎，可以在低于 100 Hz 的频率下获得增强的机电响应。在这里，我们报告了频率高达 5 kHz 时的电致伸缩应变系数 ( M ₃₁ ) 的记录值（1 kHz 时为 1.04×10 ^-14 m ² /V ² ，5 kHz 时为 3.87×10 ^-15 m ² /V ² ）使用 A 位和缺氧的钛酸钡薄膜，外延集成到 Si 上。循环次数达 600 万次后效果依然强劲且保持不变。我们的钙钛矿薄膜是非铁电性的，与化学计量的 BaTiO ₃相比表现出不同的对称性，并具有孪晶边界和纳米类极性区域的特征。我们表明，由缺陷引起的特征引起的介电弛豫与观察到的巨电致伸缩响应密切相关。这些薄膜表现出较大的热膨胀系数（2.36 × 10 ^-5 /K），这与巨大的M ₃₁一起意味着由缺陷引起的晶格非和谐性的显着增加。我们的工作为制定指导方针迈出了关键的一步，即使在无铅薄膜的较高频率下，也可以设计大型机电响应。