Raman, XRD and microscopic investigations on CeO{sub 2}-Lu{sub 2}O{sub 3} and CeO{sub 2}-Sc{sub 2}O{sub 3} systems: A sub-solidus phase evolution study
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)
- High Pressure Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)
- Material Science Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)
A sub-solidus phase evolution study was done in CeO{sub 2}-Sc{sub 2}O{sub 3} and CeO{sub 2}-Lu{sub 2}O{sub 3} systems under slow-cooled conditions from 1400 deg. C. Long-range order probing of X-ray diffraction technique is utilized in conjunction with the ability of Raman spectroscopy to detect the changes in local co-ordination. Lu{sub 2}O{sub 3} showed solubility of 30 mol% in CeO{sub 2}, thus forming an anion deficient fluorite-type (F-type) solid solution, whereas Sc{sub 2}O{sub 3} did not show any discernible solubility. A biphasic region (F+C) was unequivocally detected by Raman spectroscopy in Ce{sub 1-x}Lu{sub x}O{sub 2-x/2} (0.4{<=}x{<=}0.9) and in Ce{sub 1-x}Sc{sub x}O{sub 2-x/2} (0.1{<=}x{<=}0.9) systems. Raman spectroscopy was valuable in studying these systems since oxygen vacancies are created on doping RE{sub 2}O{sub 3} into ceria and Raman spectroscopy is very much sensitive to oxygen polarizability and local coordination. Back scattered images collected on representative compositions support the above-mentioned results. - Graphical abstract: Powder XRD and Raman spectroscopy were used in conjunction to delineate the phases present in CeO{sub 2}-Lu{sub 2}O{sub 3} and CeO{sub 2}-Sc{sub 2}O{sub 3} systems. LuO{sub 1.5} has 30 mol% miscibility, whereas Sc{sub 2}O{sub 3} has no discernible solubility in CeO{sub 2}. Raman spectroscopy clearly showed the evolution of second phase with change in concentration of the reactants thus supporting XRD data. Back scattered images obtained on representative compositions verify the results.
- OSTI ID:
- 21128394
- Journal Information:
- Journal of Solid State Chemistry, Vol. 181, Issue 8; Other Information: DOI: 10.1016/j.jssc.2008.04.001; PII: S0022-4596(08)00180-1; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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