Data di Pubblicazione:
2016
Citazione:
High-pressure compressibility and thermal expansion of aragonite / S.E.M. Palaich, R.A. Heffern, M. Hanfland, A. Lausi, A. Kavner, C.E. Manning, M. Merlini. - In: AMERICAN MINERALOGIST. - ISSN 0003-004X. - 101:7-8(2016 Aug), pp. 1651-1658. [10.2138/am-2016-5528]
Abstract:
The structure and isothermal equation of state of aragonite were determined to 40 GPa using synchrotron single-crystal X-ray techniques. In addition, powder diffraction techniques were used to determine thermal expansion between 298-673 K. At room temperature, aragonite has orthorhombic Pnma structure to 40 GPa, with an isothermal bulk modulus of 66.5(7) GPa and K' = 5.0(1). Between 25-30 GPa the aragonite unit cell begins to distort due to a stiffening of the c-axis compressibility, which is controlled by the orientation and distortion of the carbonate groups. The ambient pressure thermal expansion measurements yielded thermal expansion coefficients a(0) = 4.9(2) x 10(-5) and a(1) = 3.7(5) x 10(-8). The combined results allow the derivation of a thermal equation of state. The new data provide constraints on the behavior of carbonates and carbon cycling in the Earth's crust and mantle.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
aragonite; high pressure; thermal expansion; compressibility; equation of state; single crystal; X-ray diffraction
Elenco autori:
S.E.M. Palaich, R.A. Heffern, M. Hanfland, A. Lausi, A. Kavner, C.E. Manning, M. Merlini
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