TY - JOUR
T1 - Hydrogen bond effects on compressional behavior of isotypic minerals
T2 - high-pressure polymorphism of cristobalite-like Be(OH)2
AU - Shelton, Hannah
AU - Barkley, Madison C.
AU - Downs, Robert T.
AU - Miletich, Ronald
AU - Dera, Przemyslaw
N1 - Funding Information:
All of the experiments described in this paper were conducted by M. Barkley and were part of her Ph.D. thesis research, and the main conclusion of this work was described therein. H. Shelton conducted all structure refinements and comparative analysis. All authors contributed to writing the manuscript. The authors gratefully acknowledge the support of this study from the Chevron Corporation, BP p. l. c., the University of Arizona Galileo Circle, the Tucson Gem and Mineral Society, and Carnegie-DOE Alliance Center under cooperative agreement DE FC52-08NA28554. Development of the GSE_ADA software used for data analysis is supported by NSF Grant EAR1440005. We also thank Prof. M. Rieder and two anonymous reviewers for their keen editing and constructive criticism of this work. Portions of this project were performed at GeoSoilEnviroCARS (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory. GeoSoilEnviroCARS is supported by the National Science Foundation—Earth Sciences (EAR-0622171) and Department of Energy—Geosciences (DE-FG02-94ER14466). Use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Publisher Copyright:
© 2016, Springer-Verlag Berlin Heidelberg.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Three isotypic crystals, SiO2 (α-cristobalite), ε-Zn(OH)2 (wülfingite), and Be(OH)2 (β-behoite), with topologically identical frameworks of corner-connected tetrahedra, undergo displacive compression-driven phase transitions at similar pressures (1.5–2.0 GPa), but each transition is characterized by a different mechanism resulting in different structural modifications. In this study, we report the crystal structure of the high-pressure γ-phase of beryllium hydroxide and compare it with the high-pressure structures of the other two minerals. In Be(OH)2, the transition from the ambient β-behoite phase with the orthorhombic space group P212121 and ambient unit cell parameters a = 4.5403(4) Å, b = 4.6253(5) Å, c = 7.0599(7) Å, to the high-pressure orthorhombic γ-polymorph with space group Fdd2 and unit cell parameters (at 5.3(1) GPa) a = 5.738(2) Å, b = 6.260(3) Å, c = 7.200(4) Å takes place between 1.7 and 3.6 GPa. This transition is essentially second order, is accompanied by a negligible volume discontinuity, and exhibits both displacive and reversible character. The mechanism of the phase transition results in a change to the hydrogen bond connectivities and rotation of the BeO4 tetrahedra.
AB - Three isotypic crystals, SiO2 (α-cristobalite), ε-Zn(OH)2 (wülfingite), and Be(OH)2 (β-behoite), with topologically identical frameworks of corner-connected tetrahedra, undergo displacive compression-driven phase transitions at similar pressures (1.5–2.0 GPa), but each transition is characterized by a different mechanism resulting in different structural modifications. In this study, we report the crystal structure of the high-pressure γ-phase of beryllium hydroxide and compare it with the high-pressure structures of the other two minerals. In Be(OH)2, the transition from the ambient β-behoite phase with the orthorhombic space group P212121 and ambient unit cell parameters a = 4.5403(4) Å, b = 4.6253(5) Å, c = 7.0599(7) Å, to the high-pressure orthorhombic γ-polymorph with space group Fdd2 and unit cell parameters (at 5.3(1) GPa) a = 5.738(2) Å, b = 6.260(3) Å, c = 7.200(4) Å takes place between 1.7 and 3.6 GPa. This transition is essentially second order, is accompanied by a negligible volume discontinuity, and exhibits both displacive and reversible character. The mechanism of the phase transition results in a change to the hydrogen bond connectivities and rotation of the BeO4 tetrahedra.
KW - Behoite
KW - Beryllium hydroxide
KW - Cristobalite
KW - High pressure
KW - Hydrogen bonding
KW - Phase transitions
KW - SiO
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U2 - 10.1007/s00269-016-0818-5
DO - 10.1007/s00269-016-0818-5
M3 - Article
AN - SCOPUS:84973131450
SN - 0342-1791
VL - 43
SP - 571
EP - 586
JO - Physics and Chemistry of Minerals
JF - Physics and Chemistry of Minerals
IS - 8
ER -