Antiphase Boundaries Constitute Fast Cation Diffusion Paths in SrTiO3 Memristive Devices,Advanced Functional Materials

当前位置： X-MOL 学术 › Adv. Funct. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Antiphase Boundaries Constitute Fast Cation Diffusion Paths in SrTiO3 Memristive Devices
Advanced Functional Materials ( IF 18.5 ) Pub Date : 2020-09-16 , DOI: 10.1002/adfm.202004118
Thomas Heisig _{1,

2} , Joe Kler ₃ , Hongchu Du _{4,

5} , Christoph Baeumer _{1,

2} , Felix Hensling _{1,

2} , Maria Glöß _{1,

2} , Marco Moors _{1,

2,

6} , Andrea Locatelli ₇ , Tevfik Onur Menteş ₇ , Francesca Genuzio ₇ , Joachim Mayer _{4,

5} , Roger A. De Souza ₃ , Regina Dittmann _{1,

2}

Affiliation

Resistive switching in transition metal oxide‐based metal‐insulator‐metal structures relies on the reversible drift of ions under an applied electric field on the nanoscale. In such structures, the formation of conductive filaments is believed to be induced by the electric‐field driven migration of oxygen anions, while the cation sublattice is often considered to be inactive. This simple mechanistic picture of the switching process is incomplete as both oxygen anions and metal cations have been previously identified as mobile species under device operation. Here, spectromicroscopic techniques combined with atomistic simulations to elucidate the diffusion and drift processes that take place in the resistive switching model material SrTiO₃ are used. It is demonstrated that the conductive filament in epitaxial SrTiO₃ devices is not homogenous but exhibits a complex microstructure. Specifically, the filament consists of a conductive Ti³⁺‐rich region and insulating Sr‐rich islands. Transmission electron microscopy shows that the Sr‐rich islands emerge above Ruddlesden–Popper type antiphase boundaries. The role of these extended defects is clarified by molecular static and molecular dynamic simulations, which reveal that the Ruddlesden–Popper antiphase boundaries constitute diffusion fast‐paths for Sr cations in the perovskites structure.

中文翻译：

反相边界构成SrTiO3忆阻器件中的快速阳离子扩散路径。

基于过渡金属氧化物的金属-绝缘体-金属结构中的电阻转换依赖于在纳米级施加的电场下离子的可逆漂移。在这种结构中，导电丝的形成被认为是由电场驱动的氧阴离子迁移引起的，而阳离子亚晶格通常被认为是无活性的。切换过程的这种简单机理图是不完整的，因为氧负离子和金属阳离子都已在设备操作下被确定为可移动物质。在这里，光谱技术与原子模拟相结合，以阐明在电阻转换模型材料SrTiO _3中发生的扩散和漂移过程被使用。结果表明，外延SrTiO ₃器件中的导电丝不是均匀的，而是表现出复杂的微观结构。具体来说，灯丝由一个富含Ti ³⁺的导电区域和一个富含Sr的绝缘岛组成。透射电子显微镜显示富Sr岛出现在Ruddlesden-Popper型反相边界之上。这些扩展缺陷的作用已通过分子静态和分子动力学模拟得以阐明，这表明Ruddlesden-Popper反相边界构成钙钛矿结构中Sr阳离子的扩散快路径。

更新日期：2020-11-25

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11