High-pressure x-ray diffraction and Raman spectroscopy of HfV{sub 2}O{sub 7}
- Department of Physics, University of Missouri, Kansas City, Missouri 64110 (United States)
- Provence Materials and Microelectronics Laboratory, University of Toulon-Var, R, B.P. 20132, 83957 La Garde (France)
To study the pressure-induced changes of HfV{sub 2}O{sub 7}, energy dispersive synchrotron-based x-ray diffraction and Raman spectroscopy were performed up to 41.7 GPa and 59 GPa, respectively. X-ray diffraction indicates that HfV{sub 2}O{sub 7} undergoes two phase transitions between 0 and 42 GPa, the first occurring at 3.7{+-}0.3 GPa. The second is indicated by a gradual loss of the intensity of the Bragg peaks, suggesting pressure-induced amorphization, and is not complete even at 41.7 GPa. Using the Birch-Murnaghan equation of state to fit the x-ray diffraction data from the low-pressure phase, a bulk modulus of K=12.8{+-}0.4 GPa and a pressure derivative of the bulk modulus, K{sup '}=4.0{+-}0.5 is obtained for HfV{sub 2}O{sub 7}. Many of the Raman modes, which at zero pressure are manifolds of closely spaced peaks, separate when HfV{sub 2}O{sub 7} is placed under pressure. Additionally, under compression there is a loss of the low wave number (200-550 cm{sup -1}) modes by 2.0{+-}0.2 GPa, and at 4.7{+-}0.3 GPa a loss of the high wave number modes (700-1000 cm{sup -1})
- OSTI ID:
- 20662256
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 70, Issue 21; Other Information: DOI: 10.1103/PhysRevB.70.214114; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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