Thermoelastic parameters of Mg-sursassite and its relevance as a water carrier in subducting slabs
Articolo
Data di Pubblicazione:
2022
Citazione:
Thermoelastic parameters of Mg-sursassite and its relevance as a water carrier in subducting slabs / S. Milani, P. Fumagalli, L. Ziberna, J. Maurice, P. Lotti, D. Comboni, F. Pagliaro, M. Hanfland, G. Bais, B. Joseph, M. Merlini. - In: AMERICAN MINERALOGIST. - ISSN 0003-004X. - 107:9(2022 Sep 01), pp. 1760-1765. [10.2138/am-2022-8034]
Abstract:
We report the synthesis, at 7 GPa and 923 K, and the thermoelastic characterization, up to 16 GPa and 850 K, of a single crystal of Mg-sursassite, Mg5Al5Si6O21(OH)7. In situ high-pressure and high-temperature single-crystal diffraction allowed the study of structural variation at non-ambient conditions and the determination of bulk elastic properties. The refined parameters of a second-order Birch-Murnaghan equation of state (BM-II EoS) are V0 = 446.02(1) Å3 and KT0 = 135.6(7) GPa. The thermal expansion coefficients of a Berman-type EoS are α0 = 3.14 (5)x10^(-5) K^(-1), α1 = 2.50(16)x10^(-8) K^(-2), and V0 = 445.94(3) Å3. For comparison, the P-V EoS is determined for a natural sursassite sample, ideally Mn4Al6Si6O22(OH)6. The refined parameters of BM-II EoS [V0 = 470.2(3) Å3, KT0 = 128(4) GPa] indicate that composition has a minimal effect on elastic properties. The similarity of density and bulk properties of Mg-sursassite if compared to olivine and other anhydrous mantle minerals suggests that this phase could be overseen by geophysical methods.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Mg-sursassite; hydrous minerals; crystal structure; thermoelastic parameters
Elenco autori:
S. Milani, P. Fumagalli, L. Ziberna, J. Maurice, P. Lotti, D. Comboni, F. Pagliaro, M. Hanfland, G. Bais, B. Joseph, M. Merlini
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