Melting of magnesium oxide up to two terapascals using double-shock compression

Article

关键词: EQUATION-OF-STATE;    HIGH-PRESSURE EXPERIMENTS;    PHASE-TRANSITIONS;    LOWER MANTLE;    MGO;    PERICLASE;    MGSIO3;    TEMPERATURES;    CONSTRAINTS;    DIAGRAM;   

DOI  :  10.1103/PhysRevB.104.014106

来源: SCIE

【 摘 要 】

Constraining the melting behavior of magnesium oxide, a major constituent of gaseous and rocky planets, is key to benchmarking their evolutionary models. Using a double-shock technique, we extended the MgO melt curve measurements to 2 TPa; this is twice the pressure achieved by previous melting experiments on any material. A temperature plateau is observed between 1218 and 1950 GPa in the second-shock states, which is attributed to latent heat of melting. At 1950 GPa, the measured melting temperature is 17 600 K, which is 17% lower than recent theoretical predictions. The melting curve is steeper than that of MgSiO3, indicating that MgO is likely solid in the interior of Saturn-sized gas giants and extra-solar super-Earth planets.

【 授权许可】

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