Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1627130 | Journal of Alloys and Compounds | 2006 | 6 Pages |
Abstract
Solid state reactions of Na2U2O7 and K2U2O7 in air at 1273 K, formed mixed uranates of type (KxNa1âx)U2O7. Reduction of these mixed uranates formed (KxNa1âx)UO3 perovskite type of phase, having cubic structure for 0.5 â¤Â x â¤Â 1.0 and orthorhombic structure for 0 â¤Â x < 0.5. The kinetics of oxidation of (KxNa1âx)UO3 in air, studied by thermogravimetry showed that the reaction is diffusion controlled with an activation energy in the range 135-202 kJ/mol. The enthalpy of oxidation of these perovskite phases was determined from DTA peak area measurement and the values are in the range 40-90 kJ/mol. High temperature X-ray diffraction studies showed that the % thermal expansion increases with increase in sodium concentration in KUO3 phase.
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Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
S.K. Sali, N.K. Kulkarni, K.D. Singh Mudher,