High-pressure structural behavior and equation of state of NaZnF{sub 3}

Journal Article · Mon Jun 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.03.031· OSTI ID:21370448

Yakovlev, Sergey ^[1]; Avdeev, Maxim ^[1]; Mezouar, Mohamed ^[2]

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1. Bragg Institute, Australian Nuclear Science and Technology Organisation, 1 PBM, Menai, NSW 2234 (Australia)
2. ID-27, European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz, PB220, 38043 Grenoble CEDEX (France)

We report the results of density functional theory ab-initio calculations and monochromatic synchrotron X-ray diffraction study carried out for orthorhombic NaZnF{sub 3} in the pressure range 0-40 GPa. Perovskite-to-postperovskite phase transition was anticipated by first-principles computations and then observed in high-pressure diamond anvil cell synchrotron diffraction experiment between 14 and 22 GPa. Above 25 GPa postperovskite structure (CaIrO{sub 3} type, space group Cmcm) coexists with another phase, yet unidentified. On decompression, pure postperovskite-type structure was found to be stable down to 4 GPa; below this pressure sample contained both perovskite and postperovskite modifications. Fit of experimental P-V data to the third-order Birch-Murnaghan equation of state gave bulk moduli, K{sub P,0} 64.98+-2.67 and 69.88+-3.69 GPa for perovskite and postperovskite modifications, respectively. Both phases demonstrated strong anisotropy of compressibility. For postperovskite NaZnF{sub 3}, the highest compression was observed along the direction perpendicular to the planes of ZnF{sub 6} octahedra arrangement. - Graphical Abstract: Fit of P-V data obtained from high-pressure X-ray diffraction study of perovskite and postperovskite NaZnF{sub 3} to the third-order Birch-Murnaghan equation of state (solid line). Open and closed symbols represent experimental data corresponding to compression and decompression, respectively. Bulk moduli, K{sub 0,P}, of perovskite and postperovskite phases are 64.98+-2.67 and 69.88+-3.69 GPa.

• OSTI ID: 21370448
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 6 Vol. 182; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALKALI METAL COMPOUNDS
CALCULATION METHODS
CARBON
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DENSITY FUNCTIONAL METHOD
DIAMONDS
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUATIONS
EQUATIONS OF STATE
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MINERALS
MONOCHROMATIC RADIATION
NONMETALS
ORTHORHOMBIC LATTICES
OXIDE MINERALS
PEROVSKITE
PEROVSKITES
PHASE TRANSFORMATIONS
PRESSURE RANGE
PRESSURE RANGE GIGA PA
RADIATIONS
SCATTERING
SODIUM COMPOUNDS
SPACE GROUPS
SYMMETRY GROUPS
VARIATIONAL METHODS
X-RAY DIFFRACTION
ZINC COMPOUNDS