Ultrahigh-pressure phase equilibria for the lower mantle
نویسندگان
چکیده
منابع مشابه
High-pressure phase of brucite stable at Earth's mantle transition zone and lower mantle conditions.
We investigate the high-pressure phase diagram of the hydrous mineral brucite, Mg(OH)2, using structure search algorithms and ab initio simulations. We predict a high-pressure phase stable at pressure and temperature conditions found in cold subducting slabs in Earth's mantle transition zone and lower mantle. This prediction implies that brucite can play a much more important role in water tran...
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[1] A lower mantle S wave triplication (Scd) has been recognized for many years and appears to be explained by the recently discovered perovskite (PV) to postperovskite (PPV) phase change. Seismic observations of Scd display (1) rapid changes in strength and timing relative to S and ScS and (2) early arrivals beneath fast lower mantle regions. While the latter feature can be explained by a Clap...
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The interpretation of seismic data and computer modeling requires increased accuracy in relevant material properties in order to improve our knowledge of the structure and dynamics of the Earth’s deep interior. To obtain such properties, a complementary method to classic shock compression experiments and theoretical calculations is the use of laser-heated diamond cells, which are now producing ...
متن کاملHigh-pressure phase equilibria with compressed gases.
An apparatus is described that is capable of determining high-pressure vapor-liquid equilibrium, liquid-liquid equilibrium, solid-liquid-vapor equilibrium, vapor-liquid-liquid equilibrium, and mixture critical points and transitions. The device is capable of temperatures to 150 degrees C and pressures to 300 bars (higher with slight modifications). The construction and operation are described i...
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A new polymorph of MgSiO3 more stable than the Pbnm-perovskite phase has been identified by first-principles computations. It has the CaIrO3 structure with Cmcm symmetry and consists of SiO3 layers intercalated by eightfoldcoordinated Mg ions. High-temperature calculations within the quasiharmonic approximation give a volume change of f 1.5% and a Clapeyron slope of f 7.5F 0.3 MPa/K at f 2750 K...
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ژورنال
عنوان ژورنال: Journal of the Mineralogical Society of Japan
سال: 1983
ISSN: 1883-7018,0454-1146
DOI: 10.2465/gkk1952.16.special_207