Visualization of oxygen vacancies at CeOx/Y-HZO interface by spectrum imaging method and multivariate analysis

Electron energy loss spectroscopy—spectrum imaging measurements using a scanning transmission electron microscope are carried out to clarify the details of microstructure at the interface of the CeOx-capped Y-HZO film prepared by the chemical solution deposition (CSD) method. We confirmed that by the present CSD the independent capped layer of CeOxsuccessively deposited on Y-HZO. The crystal structure of CeOxfilm is mainly the cubic CeO2structure with Ce4+. Chemical state maps are also successfully obtained by the multivariate analysis. We found that Ce3+and Ce4+coexist in the interface layer with cubic CeO2crystal structure containing O vacancy. The results of the quantitative elemental distribution maps of energy dispersive X-ray spectroscopy also supported that O vacancies exist at the interface.