a1 Key Laboratory of Materials Modification and Key Laboratory for Solar Energy Photovoltaic of Liaoning Province, School of Materials Science and Engineering, Dalian University of Technology, 2 Linggong Road, Dalian, Liaoning 116024, China
a2 Laboratory of Fuel Cells, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
a3 Innovation Center of Nanomaterials Science for Environment and Energy, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
Microstructural evolution in a CeO2-Gd2O3 system at atomic and nanoscale levels with increasing Gd concentration has been comprehensively investigated by transmission electron microscopy. When the Gd concentration was increased from 10 to 80 at.%, the phase transformation from ceria with fluorite structure to solid solution with C-type structure was not a sudden change but an evolution in the sequence of clusters, domains, and precipitates with C-type structure in the fluorite-structured matrix. Moreover, the ordering of aggregated Gd cations and oxygen vacancies in these microstructural inhomogeneities developed continuously with increasing Gd concentration. This microstructural evolution can be further described based on the development of defect clusters containing Gd cations and oxygen vacancies.
(Received May 09 2011)
(Accepted September 12 2011)