Decaying shock studies of phase transitions in MgOSiO2 systems: implications for the Super-Earths interiors
Abstract
We report an experimental study of the phase diagrams of periclase (MgO), enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. We investigated with laser driven decaying shocks the pressure/temperature curves of MgO, MgSiO3 and Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa and 0.2-0.85 TPa respectively. A melting signature has been observed in MgO at 0.47 TPa and 9860 K, while no phase changes were observed neither in MgSiO3 nor in Mg2SiO4. An increasing of reflectivity of MgO, MgSiO3 and Mg2SiO4 liquids have been detected at 0.55 TPa -12 760 K, 0.15 TPa - 7540 K, 0.2 TPa - 5800 K, respectively. In contrast to SiO2, melting and metallization of these compounds do not coincide implying the presence of poor electrically conducting liquids close to the melting lines. This has important implications for the generation of dynamos in Super-earths mantles.
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Cite
@article{arxiv.1604.01554,
title = {Decaying shock studies of phase transitions in MgOSiO2 systems: implications for the Super-Earths interiors},
author = {R. M. Bolis and G. Morard and T. Vinci and A. Ravasio and E. Bambrink and M. Guarguaglini and M. Koenig and R. Musella and F. Remus and J. Bouchet and N. Ozaki and K. Miyanishi and T. Sekine and Y. Sakawa and T. Sano and R. Kodama and F. Guyot and A. Benuzzi-Mounaix},
journal= {arXiv preprint arXiv:1604.01554},
year = {2016}
}