Investigating the order-disorder phase transition in Nd2-xYxZr2O7via diffraction and spectroscopy

The pyrochlore-defect fluorite phase transition in the mixed-metal zirconate Nd2-xYxZr2O7 (0 <= x <= 2) solid solution was investigated using synchrotron X-ray and neutron diffraction, as well as X-ray absorption spectroscopy. Diffraction analysis revealed a two-phase region between 1.0 <= x <= 1.2. In the pyrochlore phase, Zr L-3-edge XANES analysis demonstrated a gradual change in the local coordination environment of the B site with increasing Y content that was consistent with an increase in disorder. Although Y L-3-edge XANES analysis suggested that the Y cations remained in an ordered coordination environment in the pyrochlore phase, disorder did gradually increase once the fluorite phase formed. It was found that Y cations prefer an ordered coordination environment near the phase boundary whereas Zr cations prefer a disordered coordination environment. © 2013, Royal Society of Chemistry

Keywords

Pyrochlore, Zirconium, Oxides, Raman spectroscopy, Diffraction, Spectroscopy

Citation

Blanchard, P. E. R., Liu, S., Kennedy, B. J., Ling, C. D., Zhang, Z., Avdeev, M., Cowie, B. C. C., Thomsen, L., & Jang, L. Y. (2013). Investigating the order-disorder phase transition in nd2-xyxzr2o7 via diffraction and spectroscopy. Dalton Transactions, 42(41), 14875-14882. doi:10.1039/c3dt51420j