Solid‐State Diffusional Behaviors of Functional Metal Oxides at Atomic Scale

Abstract

Metal/metal oxides have attracted extensive research interest because of their combination of functional properties and compatibility with industry. Diffusion and thermal reliability have become essential issues that require detailed study to develop atomic-scaled functional devices. In this work, the diffusional reaction behavior that transforms piezoelectric ZnO into magnetic Fe O is investigated at the atomic scale. The growth kinetics of metal oxides are systematically studied through macro- and microanalyses. The growth rates are evaluated by morphology changes, which determine whether the growth behavior was a diffusion- or reaction-controlled process. Furthermore, atom attachment on the kink step is observed at the atomic scale, which has important implications for the thermodynamics of functional metal oxides. Faster growth planes simultaneously decrease, which result in the predominance of low surface energy planes. These results directly reveal the atomic formation process of metal oxide via solid-state diffusion. In addition, the nanofabricated method provides a novel approach to investigate metal oxide evolution and sheds light on diffusional reaction behavior. More importantly, the results and phenomena of this study provide considerable inspiration to enhance the material stability and reliability of metal/oxide-based devices.

In Situ Atomic‐Scale Observation of Monolayer MoS2 Devices under High‐Voltage Biasing via Transmission Electron Microscopy

“…In situ transmission electron microscopy (TEM) is a powerful technique that not only provides high-resolution images for the atomic-scale understanding of microstructure but also helps us record a sample's response to external stimuli such as heat and bias. [27][28][29][30] Such in situ techniques have been used to study the structural and physicochemical properties of MoS 2 . For example, edge structures and unique nanostructures are tailored via in situ heating and electron beam (e-beam) irradiations to explore diverse applications of different configurations.…”