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Pressure-induced disordering and phase transformations in Eu2Zr2O7 pyrochlore |
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| Authors: | Hui Li Nana Li Yan Li Qiang Tao Yongsheng Zhao Hongyu Zhu |
| Institution: | 1. State Key Laboratory of Superhard Materials, Jilin University, Changchun, People’s Republic of China;2. College of Science, Guangxi University for Nationalities, Nanning, People’s Republic of China;3. Center for High Pressure Science and Technology Advanced Research, Shanghai, People’s Republic of China;4. College of Physics, Jilin University, Changchun, People’s Republic of China |
| Abstract: | ABSTRACTThe structural properties of pyrochlore Eu2Zr2O7 under high pressure have been studied by using Raman spectroscopy and in situ angle-dispersive X-ray diffraction (ADXRD). The results of Raman spectra indicate that Eu2Zr2O7 undergoes a reversible structural change around 21.2?GPa. The results of Rietveld refinements from in situ ADXRD data indicate that the ordered pyrochlore structure (Fd-3m) transforms to the defect-cotunnite structure (Pnma) at 26.5?GPa. The phase transition is irreversible and the transformation process is mainly induced by the accumulations of anti-site defects of the cation sublattice and Frenkel defects on the anion sublattice. Besides, the <Zr–O> bonds should play a more important role than the <Eu–O> bonds in the process of the phase transformation. |
| Keywords: | Pyrochlore synchrotron radiation Raman spectroscopy phase transformations |