X-Ray Study of Phase Transformations in Some Rare-Earth Oxide Systems
Journal Article
·
· Journal of Chemical Physics
The cubic to hexagonal phase transformation of the systems Nd/sub 2/O/ sub 3/-Sm/sub 2/O/sub 3/ and Nd/sub 2/O/sub 3/ -CeO/sub 2/ was studied by x- raydiffraction methods for zero to 20% atomic substitution of Nd by Sm or Ce. Diffraction patterns were obtatned at room temperature after heat treatments between 600 deg and l400 deg C. The patterns indicate that at elevated temperature the oxides containing Ce form a solid solution of the approximate cation composition 75% Nd-25% Ce together with excess Nd/sub 2/O/sub 3/. At 1400 deg C the solid solution was found to be cubic and the excess Nd/sub 2/O/sub 3/ to be hexagonal. The oxides containing Sm form solid solutions with cation ratios corresponding to those of the original mixture. They transform into the hexagonal phase via a monoclinic phase which is isomorphous with the B form of Sm/ sub 2/O/sub 3/. Preferred orientation effects were observed on pressed powder disks of Eu/sub 2/O/sub 3/ and Nd/sub 2/O/sub 3/ below and above their respective transition temperatures. They support an approximate identification of the monoclinic a, b, and c axes with cubic STA1l0!, STAl10!, and STA00l! directions and suggest the equtvalence of the hexagonal c axis and cubic STAlll! direction.
- Research Organization:
- Raytheon Co., Waltham, Mass.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-16-010566
- OSTI ID:
- 4809983
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 36; ISSN JCPSA6; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
THE POLYMORPHISM OF A NUMBER OF RARE EARTH OXIDES AND THEIR INTERACTION WITH WATER
NIOBIUM PHASE DIAGRAMS. Report No. 5: Columbium-Hydrogen System. Report No. 6: Columbium-Nitrogen System. Report No. 7: Columbium-Oxygen-Nitrogen System. Report No. 8: Final Technical Report Covering the Period April 15, 1957 to April 15, 1960
Synthesis of samarium sesquioxide from the thermal decomposition of samarium oxychloride
Journal Article
·
Sat Jun 01 00:00:00 EDT 1963
· At. Energ. (USSR)
·
OSTI ID:4664741
NIOBIUM PHASE DIAGRAMS. Report No. 5: Columbium-Hydrogen System. Report No. 6: Columbium-Nitrogen System. Report No. 7: Columbium-Oxygen-Nitrogen System. Report No. 8: Final Technical Report Covering the Period April 15, 1957 to April 15, 1960
Technical Report
·
Sun May 15 00:00:00 EDT 1960
·
OSTI ID:4160796
Synthesis of samarium sesquioxide from the thermal decomposition of samarium oxychloride
Journal Article
·
Thu Mar 22 00:00:00 EDT 2007
· Materials Research Bulletin
·
OSTI ID:21000609
Related Subjects
36 MATERIALS SCIENCE
ANISOTROPY
ATOMIC MODELS
CATIONS
CERIUM
CERIUM OXIDES
CONFIGURATION
CRYSTALS
DIFFRACTION
DISTRIBUTION
EUROPIUM OXIDES
HEAT TREATMENTS
HIGH TEMPERATURE
LATTICES
NEODYMIUM
NEODYMIUM OXIDES
OXIDES
PHASE DIAGRAMS
PLATES
POWDERS
PRESSURE
RARE EARTHS
SAMARIUM
SAMARIUM OXIDES
SINTERED MATERIALS
SOLID SOLUTIONS
TEMPERATURE
THERMODYNAMICS
X RADIATION
ANISOTROPY
ATOMIC MODELS
CATIONS
CERIUM
CERIUM OXIDES
CONFIGURATION
CRYSTALS
DIFFRACTION
DISTRIBUTION
EUROPIUM OXIDES
HEAT TREATMENTS
HIGH TEMPERATURE
LATTICES
NEODYMIUM
NEODYMIUM OXIDES
OXIDES
PHASE DIAGRAMS
PLATES
POWDERS
PRESSURE
RARE EARTHS
SAMARIUM
SAMARIUM OXIDES
SINTERED MATERIALS
SOLID SOLUTIONS
TEMPERATURE
THERMODYNAMICS
X RADIATION