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Title: High-pressure powder x-ray diffraction study of EuVO{sub 4}

Abstract

The high-pressure structural behavior of europium orthovanadate has been studied using in-situ, synchrotron based, high-pressure x-ray powder diffraction technique. Angle-dispersive x-ray diffraction measurements were carried out at room temperature up to 34.7 GPa using a diamond-anvil cell, extending the pressure range reported in previous experiments. We confirmed the occurrence of zircon–scheelite phase transition at 6.8 GPa and the coexistence of low- and high-pressure phases up to 10.1 GPa. In addition, clear evidence of a scheelite–fregusonite transition is found at 23.4 GPa. The fergusonite structure remains stable up to 34.7 GPa, the highest pressure reached in the present measurements. A partial decomposition of EuVO{sub 4} was also observed from 8.1 to 12.8 GPa; however, this fact did not preclude the identification of the different crystal structures of EuVO{sub 4}. The crystal structures of the different phases have been Rietveld refined and their equations of state (EOS) have been determined. The results are compared with the previous experimental data and theoretical calculations. - Graphical abstract: The high-pressure structural sequence of EuVO{sub 4}. - Highlights: • EuVO{sub 4} is studied under pressure up to 35 GPa using synchrotron XRD. • The zircón–scheelite–fergusonite structural sequence is observed. • Crystal structures are refined and equationsmore » of state determined.« less

Authors:
 [1];  [2]
  1. High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India)
  2. Departamento de Física Aplicada—ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, 46100 Valencia (Spain)
Publication Date:
OSTI Identifier:
22475648
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 226; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPARATIVE EVALUATIONS; CRYSTAL STRUCTURE; DECOMPOSITION; DIAMONDS; EQUATIONS OF STATE; EUROPIUM COMPOUNDS; PHASE TRANSFORMATIONS; POWDERS; PRESSURE DEPENDENCE; PRESSURE RANGE GIGA PA; TEMPERATURE RANGE 0273-0400 K; VANADATES; X-RAY DIFFRACTION; ZIRCON

Citation Formats

Garg, Alka B., and Errandonea, D., E-mail: daniel.errandonea@uv.es. High-pressure powder x-ray diffraction study of EuVO{sub 4}. United States: N. p., 2015. Web. doi:10.1016/J.JSSC.2015.02.003.
Garg, Alka B., & Errandonea, D., E-mail: daniel.errandonea@uv.es. High-pressure powder x-ray diffraction study of EuVO{sub 4}. United States. doi:10.1016/J.JSSC.2015.02.003.
Garg, Alka B., and Errandonea, D., E-mail: daniel.errandonea@uv.es. Sun . "High-pressure powder x-ray diffraction study of EuVO{sub 4}". United States. doi:10.1016/J.JSSC.2015.02.003.
@article{osti_22475648,
title = {High-pressure powder x-ray diffraction study of EuVO{sub 4}},
author = {Garg, Alka B. and Errandonea, D., E-mail: daniel.errandonea@uv.es},
abstractNote = {The high-pressure structural behavior of europium orthovanadate has been studied using in-situ, synchrotron based, high-pressure x-ray powder diffraction technique. Angle-dispersive x-ray diffraction measurements were carried out at room temperature up to 34.7 GPa using a diamond-anvil cell, extending the pressure range reported in previous experiments. We confirmed the occurrence of zircon–scheelite phase transition at 6.8 GPa and the coexistence of low- and high-pressure phases up to 10.1 GPa. In addition, clear evidence of a scheelite–fregusonite transition is found at 23.4 GPa. The fergusonite structure remains stable up to 34.7 GPa, the highest pressure reached in the present measurements. A partial decomposition of EuVO{sub 4} was also observed from 8.1 to 12.8 GPa; however, this fact did not preclude the identification of the different crystal structures of EuVO{sub 4}. The crystal structures of the different phases have been Rietveld refined and their equations of state (EOS) have been determined. The results are compared with the previous experimental data and theoretical calculations. - Graphical abstract: The high-pressure structural sequence of EuVO{sub 4}. - Highlights: • EuVO{sub 4} is studied under pressure up to 35 GPa using synchrotron XRD. • The zircón–scheelite–fergusonite structural sequence is observed. • Crystal structures are refined and equations of state determined.},
doi = {10.1016/J.JSSC.2015.02.003},
journal = {Journal of Solid State Chemistry},
number = ,
volume = 226,
place = {United States},
year = {Sun Mar 15 00:00:00 EDT 2015},
month = {Sun Mar 15 00:00:00 EDT 2015}
}
  • Powder X-ray diffraction experiments of sillenites Bi{sub 12}M O{sub 20} (M=Si, Ge, Ti) were performed with synchrotron radiation at the ESRF, Grenoble, at pressures up to 39 GPa (M=Si), 50 GPa (M=Ge), and 37 GPa (M=Ti), respectively. These three sillenites were investigated for the first time over such a large pressure range and they show no phase transition up to the highest pressures achieved. Birch–Murnaghan equations of state of third order were fitted to the pressure dependence of the lattice parameters. The resulting bulk moduli B{sub 0} and their pressure derivatives B′ are B{sub 0}=63(1)GPa with B′=6.6(3) (M=Si), B{sub 0}=63.0(5)GPamore » with B′=5.90(7) (M=Ge), and B{sub 0}=48(1)GPa with B′=9.4(5) (M=Ti). In the case of Bi{sub 12}SiO{sub 20} and Bi{sub 12}TiO{sub 20} the equation of state fits were restricted to pressures below 15 GPa, because the experimental data were affected by non-hydrostatic stress at higher pressures. The equation of state of neon was redetermined (V{sub 0}=11.7(6)cm{sup 3}/mol, B{sub 0}=5(1)GPa, B′=5.5(3)GPa) and its use as an internal pressure standard for diffraction experiments is discussed. A second cubic phase could be identified in our Bi{sub 12}TiO{sub 20} sample. This was attributed to eulytite-type Bi{sub 4}Ti{sub 3}O{sub 12}, which has B{sub 0}=50.9(8)GPa and B′=6.9(3). - Graphical abstract: X-ray diffraction at high pressure → Equation of state. - Highlights: • Powder X-ray diffraction experiments of sillenites were performed at high pressures. • Equations of state of sillenites Bi{sub 12}MO{sub 20} (M=Si, Ge, Ti) were determined. • The sillenite structure was shown to be stable at high hydrostatic pressure. • Sillenites are sensitive to non-hydrostatic pressure conditions in neon-loaded DACs. • An eulytite-type Bi{sub 4}Ti{sub 3}O{sub 12} phase was found to exist up to 10 GPa.« less
  • The structural behaviour of Cu 5Si under high-pressure (HP) has been studied by angular dispersive X-ray diffraction up to 49.9 GPa. The experimental results suggest that a pressure-induced isostructural phase transition occurs around 13.5 GPa as revealed by a discontinuity in volume as a function of pressure. The lattice parameter decreases with the pressure increasing for both low-pressure (LP) and HP phases of Cu 5Si. However, a plot of the lattice parameter vs. pressure shows the existence of a plateau between 11.7 and 15.3 GPa. The bulk moduli, derived from the fitting of Birch–Murnaghan equation of state, are 150(2) GPamore » and 210(3) GPa for the LP phase and the HP phase of Cu 5Si, respectively. A change in the electronic state of the copper is assumed to govern the observed structural phase transition.« less
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