Fayaz Muhammad Umer, Wang Qian, Liang Shixuan, Han Lei, Pan Feng, Song Cheng
Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
ACS Appl Mater Interfaces. 2023 Nov 28. doi: 10.1021/acsami.3c14270.
Ion injection controlled by an electric field is a powerful method to manipulate the diverse physical and chemical properties of metal oxides. However, the dynamic control of ion concentrations and their correlations with lattices in perovskite systems have not been fully understood. In this study, we systematically demonstrate the electric-field-controlled protonation of LaSrMnO (LSMO) films. The rapid and room-temperature protonation induces a colossal lattice expansion of 9.35% in tensile-strained LSMO, which is crucial for tailoring material properties and enabling a wide range of applications in advanced electronics, energy storage, and sensing technologies. This large expansion in the lattice is attributed to the higher degree of proton diffusion, resulting in a significant elongation in the Mn-O bond and octahedral tilting, which is supported by results from density functional theory calculations. Interestingly, such a colossal expansion is not observed in LSMO under compressive strain, indicating the close dependence of ion-electron-lattice coupling on strain states. These efficient modulations of the lattice and magnetoelectric functionalities of LSMO via proton diffusion offer a promising avenue for developing multifunctional iontronic devices.
由电场控制的离子注入是一种操纵金属氧化物多种物理和化学性质的强大方法。然而，钙钛矿体系中离子浓度的动态控制及其与晶格的相关性尚未得到充分理解。在本研究中，我们系统地展示了电场控制的LaSrMnO（LSMO）薄膜质子化过程。快速且在室温下的质子化在拉伸应变的LSMO中引起了9.35%的巨大晶格膨胀，这对于调整材料性能以及在先进电子、能量存储和传感技术中实现广泛应用至关重要。这种晶格的大幅膨胀归因于更高程度的质子扩散，导致Mn - O键显著伸长和八面体倾斜，这得到了密度泛函理论计算结果的支持。有趣的是，在压缩应变下的LSMO中未观察到这种巨大膨胀，这表明离子 - 电子 - 晶格耦合对应变状态密切相关。通过质子扩散对LSMO的晶格和磁电功能进行的这些有效调制为开发多功能离子电子器件提供了一条有前景的途径。
