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Effects of composition and pressure on electronic states of iron in bridgmanite

Publications associées (44)

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Primordial metallic melt in the deep mantle

Susannah McGregor Dorfman

Seismic tomography models reveal two large low shear velocity provinces (LLSVPs) that identify large-scale variations in temperature and composition in the deep mantle. Other characteristics include elevated density, elevated bulk sound speed, and sharp bo ...

Amer Geophysical Union2016

Spin and valence dependence of iron partitioning in Earth's deep mantle

Philippe Gillet, Cécile Hébert, Marco Cantoni, James Badro, Farhang Nabiei, Hélène Marie Piet, Teresa Katharina Dennenwaldt

We performed laser-heated diamond anvil cell experiments combined with state-of-the-art electron microanalysis (focused ion beam and aberration-corrected transmission electron microscopy) to study the distribution and valence of iron in Earth's lower mantl ...

Natl Acad Sciences2016

An early geodynamo driven by exsolution of mantle components from Earth's core

James Badro

Recent palaeomagnetic observations(1) report the existence of a magnetic field on Earth that is at least 3.45 billion years old. Compositional buoyancy caused by inner-core growth(2) is the primary driver of Earth's present-day geodynamo(3-5), but the inne ...

Nature Publishing Group2016

Valence and spin states of Fe were investigated in a glass of almandine (Fe3Al2Si3O12) composition to 91 GPa by X-ray emission spectroscopy and energy- and time-domain synchrotron Mossbauer spectroscopy in the diamond-anvil cell. Changes in optical propert ...

Mineralogical Soc Amer2016

Experimental studies at pressure and temperature conditions of the Earth's lower mantle have shown that iron in ferropericlase (Fp) and in Mg-silicate perovskite (Pv) undergoes a spin state transition. This electronic transition changes elastic and transpo ...

Elsevier2015

Composition dependence of spin transition in (Mg,Fe)SiO3 bridgmanite

Philippe Gillet, James Badro, Susannah McGregor Dorfman

Spin transitions in (Mg,Fe)SiO3 bridgmanite have important implications for the chemistry and dynamics of Earth's lower mantle, but have been complex to characterize in experiments. We examine the spin state of Fe in highly Fe-enriched bridgmanite synthesi ...

Mineralogical Society of America2015

Core formation and core composition from coupled geochemical and geophysical constraints

James Badro, Hélène Marie Piet

The formation of Earth's core left behind geophysical and geochemical signatures in both the core and mantle that remain to this day. Seismology requires that the core be lighter than pure iron and therefore must contain light elements, and the geochemistr ...

Natl Acad Sciences2015

Thermoelasticity of Fe2+-bearing bridgmanite

Matteo Cococcioni, Andrea Floris

We present local density approximation augmented by the Hubbard-type correction calculations of high-temperature elastic properties of bridgmanite with composition (Mg(1-x)Fex2+)SiO3 for 0

Amer Geophysical Union2015

Gradual release of strongly bound nitric oxide from Fe2(NO)2(dobdc)

Wendy Lee Queen

An iron(II)-based metal-org. framework featuring coordinatively unsatd. redox-active metal cation sites, Fe2(dobdc) (dobdc4- = 2,5-dioxido-1,4-benzenedicarboxylate), is shown to strongly bind nitric oxide at 298 K. Adsorption isotherms indicate an adsorpti ...

2015

Recent experimental measurements of the equation of state of perovskites and post-perovskites in the (Mg,Fe)SiO3 and (Mg,Fe,Al)(Fe,Al,Si)O-3 systems over a wide range of iron contents are used to constrain the effects of Fe and Al on density and bulk modul ...

Oxford University Press2014