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

• Applicant: Professorin Dr. Cynthia A. Volkert
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 319436625

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.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1959: Manipulation of matter controlled by electric and magnetic fields: Towards novel synthesis and processing routes of inorganic materials