In-Situ Electron Microscopy Studies of Flash Annealing in Oxide Ceramics

尽管闪速烧结在陶瓷材料加工中具有广泛的应用潜力，但其物理成因仍不清楚。在这个SPP 1959项目的第二阶段，我们建议测试闪的潜在机制与电阻开关相同的假设。这个想法是由我们的第一阶段的结果所激发的，我们在TEM内的ZnO薄膜中实现了闪光事件，并发现了与电阻开关的相似之处。我们将继续研究全致密ZnO的闪蒸退火，以关注闪蒸引起的材料特性变化，而不是形貌变化，并将使用原位和非原位TEM方法比较闪蒸和电阻开关样品的微观结构。具体来说，我们将在闪现样品中寻找导电细丝，因为它们被广泛接受为金属氧化物中电阻开关的基本结构。此外，我们将利用原位透射电镜来研究不同气氛对闪蒸事件的影响，这是由最近在水蒸气中观察到的ZnO室温闪蒸引起的。

Despite the wide application potential of flash sintering for processing ceramic materials, the physical origins of the effect remain unclear. In the second phase of this SPP 1959 project, we propose to test the hypothesis that the underlying mechanisms for flash are the same as for resistive switching. This idea is motivated by our results of the first period, where we achieved a flash event in a ZnO thin film inside the TEM and found parallels to resistive switching. We will continue to work on flash annealing of fully dense ZnO, in order to focus on flash-induced changes in intrinsic material properties rather than morphology changes, and will compare microstructures of flashed and resistively switched specimens using in-situ and ex-situ TEM methods. Specifically, we will search for conducting filaments in flashed specimens, since they are widely accepted as the basic structure responsible for resistive switching in metal oxides. In addition, we will use in-situ TEM to investigate the effect of different atmospheres on the flash event, motivated by recent observations of room temperature flash of ZnO in water vapor.