@article{737cdaae9ab643188376fc319a97871d,
title = "Equation of state of the α-Pb O2 and Pa 3 -type phases of Ge O2 to 120 GPa EQUATION of STATE of the α-Pb O2 and ... DUTTA, WHITE, GREENBERG, PRAKAPENKA, and DUFFY",
abstract = "The compression behavior of crystalline and amorphous germania holds considerable interest as an analog for silica and for understanding the structural response of AX2 compounds generally. In this paper, the α-PbO2-type and Pa3-type polymorphs of GeO2 were investigated under high pressure using angle-dispersive synchrotron x-ray diffraction in the laser-heated diamond anvil cell. Theoretical calculations based on density functional theory were also performed. The experimental pressure-volume data were fitted to third-order Birch-Murnaghan equations of state. The fit parameters for the α-PbO2 type are V0=53.8(2){\AA}3,K0T=293(7)GPa with fixed K0T′=4, where V,KT, and KT′ are the volume, isothermal bulk modulus, and pressure derivative of the bulk modulus and the subscript zero refers to ambient conditions. The corresponding parameters for the Pa3-type phase are V0=50.3(3){\AA}3,K0T=342(12)GPa with fixed K0T′=4. The theoretical calculations are in good agreement with the experimental results with slight underestimation and overestimation of V0 and K0T, respectively. A theoretical Hugoniot was calculated from our data and compared to shock equation of state data for vitreous and rutile-type GeO2. The high-pressure phase observed on the Hugoniot is most consistent with either the α-PbO2-type or CaCl2-type phase. Finally, we have compared our data on crystalline germania with existing studies on the corresponding phases of SiO2 to better understand the effects of cation substitution on phase transformations and equations of state in group 14 dioxides.",
author = "R. Dutta and White, {Claire Emily} and E. Greenberg and Prakapenka, {V. B.} and Duffy, {Thomas S.}",
note = "Funding Information: The authors are grateful to S. J. Tracy, C. V. Stan, J. K. Wicks, and S. Tkachev for helpful comments on the paper and/or experimental assistance. The work was funded by the NSF (Grant No. EAR-1415321). Use of the Advanced Photon Source, an Office of Science User Facility, US Department of Energy (DOE) is acknowledged. GeoSoilEnviroCARS (GSE-CARS, Sector 13), is supported by the NSF Earth Sciences (Grant No. EAR-1634415) and the DOE, Geosciences (Grant No. DE-FG02-94ER14466). The gas-loading facility at GSE-CARS is partially supported by the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR Grant No. 1606856. This research used resources of the Advanced Photon Source, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Funding Information: The authors are grateful to S. J. Tracy, C. V. Stan, J. K. Wicks, and S. Tkachev for helpful comments on the paper and/or experimental assistance. The work was funded by the NSF (Grant No. EAR-1415321). Use of the Advanced Photon Source, an Office of Science User Facility, US Department of Energy (DOE) is acknowledged. GeoSoilEnviroCARS (GSECARS, Sector 13), is supported by the NSF Earth Sciences (Grant No. EAR-1634415) and the DOE, Geosciences (Grant No. DE-FG02-94ER14466). The gas-loading facility at GSECARS is partially supported by the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR Grant No. 1606856. This research used resources of the Advanced Photon Source, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Publisher Copyright: {\textcopyright} 2018 American Physical Society.",
year = "2018",
month = oct,
day = "11",
doi = "10.1103/PhysRevB.98.144106",
language = "English (US)",
volume = "98",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "14",
}