Perturbed angular-correlation spectroscopy of defects in ceria

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:5475054

Wang, Ruiping

Dilute indium dopants in cerium oxides were studied by {sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. Oxygen concentration in the cerium oxides was controlled through doping or high-temperature vacuum cleaning; four different defect complexes were found. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent, the aftereffects interaction. In undoped ceria, indium always forms a defect complex with a tightly bound oxygen vacancy (A site). The A site has an axially symmetric electric field gradient (efg) and V{sub zz}(lat) is 0.87 (10{sup 16}Volts/cm{sup 2}). The efg symmetry axis can reorient its direction under thermal activation. On increasing the oxygen-vacancy concentration by annealing the ceria sample at high temperatures or doping ceria with more than 0.4% Y, another two defect complexes (B and C sites) are found. The B site is the complex of the A site plus another oxygen vacancy distant from the indium probe, and the C site is a complex of the A site plus another oxygen vacancy on the opposite side of the indium atom from the indium probe, and the C site is a complex of the A site plus another oxygen vacancy on the opposite side of the indium atom from the first vacancy. When ceria is doped with more than 300ppm Nb, the A site is replaced by an unperturbed site and another defect complex (D site).

• Research Organization: Oregon State Univ., Corvallis, OR (United States)
• OSTI ID: 5475054
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CERIUM OXIDES
CRYSTAL DEFECTS
INDIUM 111
OXYGEN
PERTURBED ANGULAR CORRELATION
QUANTITY RATIO
SPECTROSCOPY
VACANCIES
ANGULAR CORRELATION
BETA DECAY RADIOISOTOPES
CERIUM COMPOUNDS
CHALCOGENIDES
CORRELATIONS
CRYSTAL STRUCTURE
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
INDIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MINUTES LIVING RADIOISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXIDES
OXYGEN COMPOUNDS
POINT DEFECTS
RADIOISOTOPES
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