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DS: Fachverband Dünne Schichten
DS 14: Transport Properties
DS 14.1: Talk
Thursday, March 21, 2024, 09:30–09:45, A 060
Influence of the microstructure on the impedance of microstructured ceria thin films — •Jan L. Dornseifer1,2, Janis K. Eckhardt2,3, Mattias T. Elm1,2,3, and Peter J. Klar1,2 — 1Institute of Experimental Physics I, Justus-Liebig-University, Giessen, Germany — 2Center for Materials Research (ZfM), Justus-Liebig-University, Giessen, Germany — 3Institute of Physical Chemistry, Justus-Liebig-University, Giessen, Germany
Polycrystalline thin films with mixed electronic and ionic conductive properties are essential for many energy devices. Their charge transport properties are often characterized by impedance spectroscopy (IS). The IS data is usually evaluated by using simple circuit models to correlate macroscopic properties with microscopic transport processes.
Here, we show that the microstructure in polycrystalline ceria thin films has a significant impact on the impedance. An experimental approach has been developed to prepare ceria microstructures on sapphire substrates. Utilizing a lithographic process, single ceria microstructures were electrically contacted and investigated by IS. Novel computer-aided simulations based on an impedance network model are used to analyze the experimental IS data. In these simulations, the real ceria microstructure is accurately mapped and implemented. The results show that the influence of the microstructure on the impedance is stronger than previously thought. Further investigations are promising for establishing a new correlation model.
Keywords: Cerium oxide; Impedance spectroscopy; Charge transport; Microstructure