Crystal chemistry of the rhombohedral MO{sub 3} {center_dot}3R{sub 2}O{sub 3} compounds
Phase relationship studies on the UO/sub 2/-UO/sub 3/-Y/sub 2/O/sub 3/ ternary system showed the formation of face-centered cubic solid solutions, body- centered cubic solid solutions, and two rhombohedral phases. Both rhombohedral phases exist at a definite chemical composition, one of which (Rh I) can be expressed by the formula (U/sub x/, Y/sub 7-x/)O/sub 12/ where x = 1 to 3.4. For values of x greater than 2.8, low temperature oxidation produces a second rhombohedral structure (Rh II) of composition (U/sub y/, Y/sub 8- gamma /)O/sub 15/ where y = 2 to 3.9. The rhombohedral I crystal structure is characteristic of a large family of new compounds formed between rare earth oxides and UO/sub 3/ , WO/sub 3/, or MoO/sub 3/. Crystallographic data on these isostructural compounds are presented. The influence of ionic size and valence upon the formation and stability of this structure are discussed. (auth)
- Research Organization:
- General Electric Co., Cincinnati, OH (United States)
- Sponsoring Organization:
- U.S. Air Force, Div. of Reactor Development
- DOE Contract Number:
- AF(40-1)-2847
- NSA Number:
- NSA-18-006836
- OSTI ID:
- 4878733
- Report Number(s):
- CONF-45-1; AED-Conf-63-203-1; TM-63-10-2
- Resource Relation:
- Conference: American Ceramic Society Basic Science Division Meeting, Washington, D.C. (United States), 6-8 Oct 1963
- Country of Publication:
- United States
- Language:
- English
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ARGON 41
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LOW TEMPERATURE
MIXING
MOLYBDENUM OXIDES
OPERATION
OXIDATION
OXIDES
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PRODUCTION
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URANIUM DIOXIDE
URANIUM TRIOXIDE
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