论文标题
铁弹性转换驱动的巨大剪切应变和在混合铁电中的压电性
Ferroelastic-switching-driven colossal shear strain and piezoelectricity in a hybrid ferroelectric
论文作者
论文摘要
可以产生大型可控菌株的材料被广泛用于形状记忆设备，执行器和传感器。已经做出了巨大的努力来改善各种材料系统的应变输出。其中，铁弹性过渡基于电动铁/压电和热或磁性形状的记忆合金中的巨大巨型可逆菌株。但是，常规铁电的大型铁弹性转换非常具有挑战性，而磁和热控制对于应用不可取。在这里，我们证明了在杂种铁电（C6H5N（CH3）3CDCL3）中前所未有的大型剪切应变。应变反应比表现最佳的常规铁电聚合物和氧化物高两个数量级。它是通过无机键转换来实现的，并通过大型有机部分的结构限制来促进，从而阻止了不希望的180度极化切换。此外，BR取代可以有效地软化键，并导致巨大的剪切压电系数（D35〜4800 pm/v）在实心溶液的BR末端C6H5N（CH3）3CDBR3XCL3（1-X）中。该化合物的优质机电特性有望在轻质和高能密度设备中潜力，此处描述的策略应激发基于混合铁电的基于混合动力的下一代压电和电活性材料的发展。
Materials that can produce large controllable strains are widely used in shape memory devices, actuators and sensors. Great efforts have been made to improve the strain outputs of various material systems. Among them, ferroelastic transitions underpin giant reversible strains in electrically-driven ferro/piezoelectrics and thermally- or magneticallydriven shape memory alloys. However, large-strain ferroelastic switching in conventional ferroelectrics is very challenging while magnetic and thermal controls are not desirable for applications. Here, we demonstrate an unprecedentedly large shear strain up to 21.5 % in a hybrid ferroelectric, C6H5N(CH3)3CdCl3. The strain response is about two orders of magnitude higher than those of top-performing conventional ferroelectric polymers and oxides. It is achieved via inorganic bond switching and facilitated by the structural confinement of the large organic moieties, which prevents the undesired 180-degree polarization switching. Furthermore, Br substitution can effectively soften the bonds and result in giant shear piezoelectric coefficient (d35 ~ 4800 pm/V) in Br-rich end of the solid solution, C6H5N(CH3)3CdBr3xCl3(1-x). The superior electromechanical properties of the compounds promise their potential in lightweight and high energy density devices, and the strategy described here should inspire the development of next-generation piezoelectrics and electroactive materials based on hybrid ferroelectrics.
