Order-disorder transition in Nd{sub 2-y}Gd{sub y}Zr{sub 2}O{sub 7} pyrochlore solid solution: An X-ray diffraction and Raman spectroscopic study
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)
- High Pressure Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)
- UGC-DAE CSR, University Campus, Khandwa Road, Indore 452 017 (India)
Powder X-ray diffraction (XRD) and Raman spectroscopic study of order-disorder-phase transition with increase in the content of Gd in Nd{sub 2-y}Gd{sub y}Zr{sub 2}O{sub 7} solid solution is being reported. It has been observed from Rietveld analysis that with increase in concentration of Gd in Nd{sub 2-y}Gd{sub y}Zr{sub 2}O{sub 7}, the value of the x parameter of the 48f oxygen changes from 0.332(1) to 0.343(1) with a sudden change in the slope for y=1.8, which indicates that the structure is transforming from ordered pyrochlore to disordered pyrochlore. In addition to that a sudden and drastic change in the Raman spectra including changes in the position and width of several Raman modes beyond y{>=}1.8 has also been observed which has been correlated with increasing disorder. Based on these studies, it is suggested that there is a discontinuous order-disorder transition from 'perfect pyrochlore' to 'defect pyrochlore' phase in Nd{sub 2-y}Gd{sub y}Zr{sub 2}O{sub 7} solid solution. - Graphical abstract: Raman spectra of Nd{sub 2-y}Gd{sub y}Zr{sub 2}O{sub 7} with increasing proportion of Gd in Nd{sub 2-y}Gd{sub y}Zr{sub 2}O{sub 7} series. A transition from ordered pyrochlore to disordered pyrochlore can be seen at y{approx}1.8.
- OSTI ID:
- 21049493
- Journal Information:
- Journal of Solid State Chemistry, Vol. 180, Issue 10; Other Information: DOI: 10.1016/j.jssc.2007.07.007; PII: S0022-4596(07)00280-0; Copyright (c) 2007 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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