Speciation of uranium and doping induced defects in Gd1.98U0.02Zr2O7: Photoluminescence, X-ray photoelectron and positron annihilation lifetime spectroscopy.
- Resource Type
- Article
- Authors
- Gupta, Santosh K.; Reghukumar, C.; Pathak, Nimai; Sudarshan, K.; Tyagi, D.; Mohapatra, M.; Pujari, P.K.; Kadam, R.M.
- Source
- Chemical Physics Letters. Feb2017, Vol. 669, p245-250. 6p.
- Subject
- *URANIUM isotopes
*CHEMICAL speciation
*DOPING agents (Chemistry)
*POINT defects
*X-ray photoelectron spectra
*POSITRON annihilation
- Language
- ISSN
- 0009-2614
Based on photoluminescence spectroscopy it was inferred that uranium stabilizes as both U(IV) as well as U(VI) in Gd 2 Zr 2 O 7 which was also corroborated using X-ray photo electron spectroscopy (XPS). Absence of equidistant vibronic structure in emission spectrum of Gd 1.98 U 0.02 Zr 2 O 7 confirmed that U(VI) stabilizes in the form of UO 6 6− . Based on luminescence lifetime it was inferred that majority of UO 6 6− stabilizes at both Gd 3+/ Zr 4+ whereas U 4+ stabilizes only at Zr 4+ sites. The positron lifetime doesn’t change on uranium doping indicating the formation of antisite defect. Infact it is this antisite defect in Gd 1.98 U 0.02 Zr 2 O 7 which favours the stabilization of its fluorite phase. [ABSTRACT FROM AUTHOR]