Origin of Fe 3+ in Fe-containing, Al-free mantle silicate perovskite
نویسندگان
چکیده
منابع مشابه
Stability of Fe,Al-bearing bridgmanite in the lower mantle and synthesis of pure Fe-bridgmanite
The physical and chemical properties of Earth's mantle, as well as its dynamics and evolution, heavily depend on the phase composition of the region. On the basis of experiments in laser-heated diamond anvil cells, we demonstrate that Fe,Al-bearing bridgmanite (magnesium silicate perovskite) is stable to pressures over 120 GPa and temperatures above 3000 K. Ferric iron stabilizes Fe-rich bridgm...
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[1] The electronic spin and valence states of Fe in post‐ perovskite ((Mg0.75Fe0.25)SiO3) have been investigated by synchrotron X‐ray diffraction, Mössbauer and X‐ray emission spectroscopy at 142 GPa and 300 K. Rietveld refinement of the X‐ray diffraction patterns revealed that our sample was dominated by CaIrO3‐type post‐perovskite. Combined Mössbauer and X‐ray emission results show that Fe in...
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The thickness and temperature dependences of the interlayer exchange coupling in well-defined molecular beam epitaxy-grown Fe/Si/Fe sandwich structures have been studied. The biquadratic coupling shows a strong temperature dependence in contrast to the bilinear coupling. Both depend exponentially on thickness. These observations can be well understood in the framework of Slonczewski's loose spi...
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We investigate the shear response of possible slip systems activated in pure and Fe-bearing MgSiO(3) post-perovskite (PPv) through ab initio generalized stacking fault (GSF) energy calculations. Here we show that the [100](001) slip system has the easiest response to plastic shear among ten possible slip systems investigated. Incorporation of Fe(2+) decreases the strength of all slip systems bu...
متن کاملDensity - functional study of Fe 3 Al : LSDA versus GGA
The local-spin-density approximation and the generalized-gradient approximation ~GGA! are used to perform density-functional total-energy calculations at zero temperature for Fe3Al in the ordered D03 and L12 structures. Our calculations show that commonly used GGA functionals fail to predict the experimentally stable D03 structure as the one with the lower total energy. This qualitative discrep...
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ژورنال
عنوان ژورنال: Earth and Planetary Science Letters
سال: 2015
ISSN: 0012-821X
DOI: 10.1016/j.epsl.2014.11.006