Phase separation in 12 mol% ceria-doped zirconia induced by heat treatment in H[sub 2] and Ar

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1992.tb05514.x· OSTI ID:6973464

Zhu, H Y ^[1]; Hirata, T; Muramatsu, Y ^[2]

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1. Dept. of Materials Science and Engeineering, Zhejiang Univ., Hangzhou 310027 (China)
2. National Research Inst. for Metals, Tokyo (Japan)

The phase separation in 12 mol % CeO[sub 2]-ZrO[sub 2] ceramic heat-treated in a mixture of H[sub 2] and Ar was investigated by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, and Raman scattering. After heat treatment at temperatures above 1200[degrees] C, the tetragonal solid-solution phase separated into Zr[sub 2]Ce[sub 2]O[sub 7] and the monoclinic phase. Raman scattering measurements also provided supplementary evidence for the phase separation. XPS showed that the valence change from Ce[sup 4+] to Ce[sup 3+] predominantly occurred, whereas the reduction from Zr[sup 4+] to Zr[sup 3+] took place above 1200[degrees] C. In this paper it is concluded, that in the highly reduced sample, where the valence changes from Ce[sup 4+] (Zr[sup 4+] to Ce[sup 3+] (Zr[sup 3+]), the phase separation is noticeably promoted. Below 1000[degrees] C the phase separation was suppressed because of no appreciable valence change to trigger the phase separation.

• OSTI ID: 6973464
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 75:10; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ARGON
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL DOPING
DIFFRACTION
DOPED MATERIALS
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
FLUIDS
FOURIER TRANSFORM SPECTROMETERS
GASES
HEAT TREATMENTS
HYDROGEN
INFRARED SPECTRA
IONIZING RADIATIONS
MATERIALS
MEASURING INSTRUMENTS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHOTOELECTRON SPECTROSCOPY
RADIATIONS
RAMAN EFFECT
RARE EARTH COMPOUNDS
RARE GASES
SCATTERING
SPECTRA
SPECTROMETERS
SPECTROSCOPY
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TRANSITION ELEMENT COMPOUNDS
VALENCE
X RADIATION
X-RAY DIFFRACTION
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES