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Phase transitions of BaCO3 at high pressures

Published online by Cambridge University Press:  05 July 2018

S. Ono*
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan
J. P. Brodholt
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
G. D. Price
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
*

Abstract

First-principles simulations and high-pressure experiments were used to study the stability of BaCO3 carbonates at high pressures. Witherite, which is orthorhombic and isotypic with CaCO3 aragonite, is stable at ambient conditions. As pressure increases, BaCO3 transforms from witherite to an orthorhombic post-aragonite structure at 8 GPa. The calculated bulk modulus of the post-aragonite structure is 60.7 GPa, which is slightly less than that from experiments. This structure shows an axial anisotropicc ompressibility and the a axis intersects with the c axis at 70 GPa, which implies that the pressure-induced phase transition reported in previous experimental study is misidentified. Although a pyroxene-like structure is stable in Mg- and Ca-carbonates at pressures >100 GPa, our simulations showed that this structure does not appear in BaCO3.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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References

Antao, S.M. and Hassan, I. (2007) BaCO3: high-temperature crystal structures and the Pmcn → Rim phase transition at 811°C. Physics and Chemistry of Minerals, 34, 573580.CrossRefGoogle Scholar
Arapan, S., de Almeida, IS. and Ahuja, R. (2007) Formation of sp hybridized bonds and stability of CaCO3 at very high pressure. Physical Review Letters, 98, 268501.CrossRefGoogle ScholarPubMed
Birch, F. (1947) Finite elastic strain of cubic crystals. Physical Review, 71, 809824.CrossRefGoogle Scholar
Blochl, P.E. (1994) Projector augmented-wave method. Physical Review B, 50, 1795317979.CrossRefGoogle ScholarPubMed
Gillan, M.J., Alfe, D., Brodholt, J.P., Vocadlo, L. and Price, G.D. (2006) First-principles modeling of Earth and planetary materials at high pressures and temperatures. Report on Progress in Physics, 69, 23652441.CrossRefGoogle Scholar
Holl, CM., Smyth, J.R., Laustsen, H.M.S., Jacobsen, S.D. and Downs, R.T. (2000) Compression of witherite to 8 GPa and the crystal structure of BaCO3II. Physics and Chemistry of Minerals, 27, 467473.CrossRefGoogle Scholar
Holmes, N.C., Moriarty, J.A., Gathers, G.R. and Nellis, W.J. (1989) The equation of state of platinum to 660 GPa (6.6 Mbar). Journal of Applied Physics, 66, 29622967.CrossRefGoogle Scholar
Kresse, G. and Furthmiiller, J. (1996) Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Physical Review B, 54, 1116911186.CrossRefGoogle ScholarPubMed
Kresse, G. and Joubert, D. (1999) From ultrasoft pseudopotentials to the projector augmented-wave method. Physical Review B, 59, 17581775.CrossRefGoogle Scholar
Oganov, A.R., Glass, C.W. and Ono, S. (2006) High-pressure phases of CaCO3: crystal structure prediction and experiment. Earth and Planetary Science Letters, 241, 95103.CrossRefGoogle Scholar
Ono, S. (2007) New high-pressure phases in BaCO3. Physics and Chemistry of Minerals, 34, 215221.CrossRefGoogle Scholar
Ono, S., Ohishi, Y., Isshiki, M. and Watanuki, T. (2005) In situ X-ray observations of phase assemblages in peridotite and basalt compositions at lower mantle conditions: implications for density of subducted oceanic plate. Journal of Geophysical Research, 110, B02208.CrossRefGoogle Scholar
Ono, S., Kikegawa, T. and Ohishi, Y. (2007) High-pressure transition of CaCO3 . American Mineralogist, 92, 12461249.CrossRefGoogle Scholar
Ono, S., Brodholt, J.P. and Price, G.D. (2008) Structural phase transitions in IrO2 at high pressures. Journal of Physics: Condensed Matter, 20, 045202.Google Scholar
Perdew, J.P., Burke, K. and Ernzerhof, M. (1996) Generalized gradient approximation made simple. Physical Review Letters, 77, 38653868.CrossRefGoogle ScholarPubMed
Skorodumova, N.V., Belonoshko, A.B., Huang, L., Ahuja, R. and Johansson, B. (2005) Stability of the MgCO3 structures under lower mantle conditions. American Mineralogist, 90, 10081011.CrossRefGoogle Scholar