Decaying shock studies of phase transitions in MgO-SiO2 systems: Implications for the super-Earths' interiors

被引：54

作者：

Bolis, R. M. ^{[1
,2
]}

Morard, G. ^{[3
]}

Vinci, T. ^{[1
,2
]}

Ravasio, A. ^{[1
,2
]}

Bambrink, E. ^{[1
,2
]}

Guarguaglini, M. ^{[1
,2
]}

Koenig, M. ^{[1
,2
,4
]}

Musella, R. ^{[5
]}

Remus, F. ^{[6
]}

Bouchet, J. ^{[6
]}

Ozaki, N. ^{[7
,8
]}

Miyanishi, K. ^{[8
]}

Sekine, T. ^{[9
]}

Sakawa, Y. ^{[10
]}

Sano, T. ^{[10
]}

Kodama, R. ^{[4
,7
,8
]}

Guyot, F. ^{[3
]}

Benuzzi-Mounaix, A. ^{[1
,2
]}

机构：

[1] Univ Paris Saclay, CEA, Ecole Polytech, LULI CNRS, F-91128 Palaiseau, France

[2] Univ Paris 06, Univ Paris 04, CNRS, LULI, Pl Jussieu, F-75252 Paris 05, France

[3] Univ Paris 06, Univ Paris 04, Museum Natl Hist Nat,UMR 7590, Inst Mineral Phys Materiaux & Cosmochim,CNRS,IRD, Paris, France

[4] Osaka Univ, Inst Acad Initiat, Suita, Osaka, Japan

[5] Univ Paris Diderot, CNRS, Observ Paris, LUTH, Meudon, France

[6] CEA, DIF, DAM, Arpajon, France

[7] Osaka Univ, Grad Sch Engn, Suita, Osaka, Japan

[8] Osaka Univ, Photon Pioneers Ctr, Suita, Osaka, Japan

[9] Hiroshima Univ, Dept Earth & Planetary Syst Sci, Higashihiroshima, Japan

[10] Osaka Univ, Inst Laser Engn, Suita, Osaka, Japan

来源：

GEOPHYSICAL RESEARCH LETTERS | 2016年 / 43卷 / 18期

关键词：

LIQUID; MGSIO3; TEMPERATURES; DYNAMICS; MG2SIO4; SIO2; MGO;

D O I：

10.1002/2016GL070466

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

We report an experimental study of the phase diagrams of MgO, MgSiO3, and Mg2SiO4 at high pressures. We measured the shock compression response, including pressure-temperature Hugoniot curves of MgO, MgSiO3, and Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa, and 0.2-0.85 TPa, respectively, using laser-driven decaying shocks. A melting signature has been observed in MgO at 0.47 +/- 0.04 TPa and 9860 +/- 810 K, while no such phase changes were observed either in MgSiO3 or in Mg2SiO4. Increases of reflectivity of MgO, MgSiO3, and Mg2SiO4 liquids have been detected above 0.55 TPa (12760 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 poorly electrically conducting liquids close to the melting lines. This has important implications for the generation of dynamos in super-Earth's mantles.

引用

页码：9475 / 9483

页数：9

共 44 条

[21] Ab initio investigation of a possible liquid liquid phase transition in MgSiO3 at megabar pressures [J].