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X‐ray Absorption Studies of Ceria with Trivalent Dopants
Author(s) -
Li Ping,
Chen IWei,
PennerHahn James E.,
Tien TsengYing
Publication year - 1991
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1991.tb04328.x
Subject(s) - xanes , extended x ray absorption fine structure , crystallography , absorption (acoustics) , dopant , x ray absorption fine structure , ion , x ray , oxygen , chemistry , cluster (spacecraft) , doping , materials science , analytical chemistry (journal) , spectroscopy , absorption spectroscopy , physics , composite material , optoelectronics , organic chemistry , quantum mechanics , chromatography , computer science , programming language
The local structural environments of Sc 3+ and Gd 3+ in ceria were studied for the first time by using EXAFS (extended X‐ray absorption fine structure) and XANES (X‐ray absorption near edge structure) spectroscopy. Our results indicate that Sc 3+ in 10‐mol%‐Sc 2 O 3 ‐doped ceria has a 7‐fold‐coordinated Sc‐ordered structure with two different Sc─O distances (2.13 and 2.26 Å). An octahedrally coordinated Sc─O cluster is present in 5 mol% Sc 2 O 3 ─5 mol% Gd 2 O 3 ─CeO 2 , because of the strong scavenging effect of Sc 3+ ions on oxygen vacancies created by Gd 3+ . The Gd 3+ in this sample is largely unassociated. Sc 2 O 3 (5 mol%) and Gd 2 O 3 (5 or 10 mol%) form random solid solutions with CeO 2 . These results are consistent with the current concept of defect structures in this structural family.