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High P,T Nuclear Resonance Studies of Lower Mantle Phases:

High P,T Nuclear Resonance Studies of Lower Mantle Phases: New Insights into Lower Mantle Properties and Processes. Catherine McCammon & Leonid Dubrovinsky Bayerisches Geoinstitut , Universität Bayreuth. 5th Berichtskolloquium , SPP 1236 . 25-28 September 2012.

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High P,T Nuclear Resonance Studies of Lower Mantle Phases:

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  1. High P,T Nuclear Resonance Studies of Lower Mantle Phases: New Insights into Lower Mantle Properties and Processes Catherine McCammon& Leonid Dubrovinsky BayerischesGeoinstitut, Universität Bayreuth 5th Berichtskolloquium, SPP 1236 25-28 September 2012 C. McCammon:High P,T Nuclear Resonance Studies ...

  2. The big picture I: valence/spin and mantle dynamics McCammon (2006) Mössbauer spectroscopy/Nuclear forward scattering (NFS) C. McCammon:High P,T Nuclear Resonance Studies ...

  3. The big picture II: geophysical data interpretation van der Hilst (2004) Nuclear inelastic scattering (NIS) C. McCammon:High P,T Nuclear Resonance Studies ...

  4. Measurements along the geotherm Image from S. Sinogeikin based on an image by G. Shen C. McCammon:High P,T Nuclear Resonance Studies ...

  5. Portable double-sided laser heating: schematic Kupenko et al. in review C. McCammon:High P,T Nuclear Resonance Studies ...

  6. Portable double-sided laser heating: setup Kupenko et al. in review ESRF ID18 Mg0.8Fe0.2O at 29 GPa C. McCammon:High P,T Nuclear Resonance Studies ...

  7. Spin transitions in (Mg,Fe)(Si,Al)O3 perovskite B site S=2 S=5/2 S=0 S=1/2 Fe2+ Fe3+ A site S=5/2 S=3/2 S=1/2 S=2 S=1 S=0 Fe2+ Fe3+ C. McCammon:High P,T Nuclear Resonance Studies ...

  8. Fe2+ spin state in lower mantle silicate perovskite McCammon et al. 2008 McCammon et al. 2010 Fe2+ high-spin intermediate-spin low-spin C. McCammon:High P,T Nuclear Resonance Studies ...

  9. What about Fe3+ in (Mg,Fe)(Si,Al)O3 pv? 3 Fe2+→ 2 Fe3+ + Fe0 3 Fe2+→ 2 Fe3+ + Fe0 C. McCammon:High P,T Nuclear Resonance Studies ...

  10. Reports in the literature High-spin to low-spin transition in Fe3+: Theoretical Hsu et al. (2011) PRL Experimental Catalli et al. (2010) EPSL Catalli et al. (2011) EPSL Fujino et al. (2012) EPSL Catalli et al. 2011 B site: HS-LS A site: no spin transition Fujino et al. 2012 C. McCammon:High P,T Nuclear Resonance Studies ...

  11. The challenge to resolve Fe3+ (Mg,Fe)(Si,Al)O3perovskite conventional NFS 0 GPa 0 GPa Fe2+-Fe3+ Fe3+ Relative transmission Counts Velocity (mm/s) Time(ns) C. McCammon:High P,T Nuclear Resonance Studies ...

  12. (Mg,Fe)(Si,Al)O3 perovskite 93 GPa Synchrotron Mössbauer source with DAC Potapkin et al. (2012) ESRF, ID18 7 days 10 min C. McCammon:High P,T Nuclear Resonance Studies ...

  13. Focus on Fe3+ spin state Potapkin et al. in review (Mg,Fe)(Si,Al)O3 perovskite 80% Fe3+ Fe3+ 50% Fe3+ 3 GPa low-spin Fe3+ 75 GPa 38 GPa 75 GPa hot 67 GPa Fe2+ 20% Fe3+ 93 GPa No evidence for low-spin Fe3+ C. McCammon:High P,T Nuclear Resonance Studies ...

  14. Iron spin state in lower mantle silicate perovskite McCammon et al. 2008 McCammon et al. 2010 Potapkin et al. in review Fe2+ Fe3+ high-spin all high-spin intermediate-spin low-spin C. McCammon:High P,T Nuclear Resonance Studies ...

  15. Electrical conductivity measurements C. McCammon:High P,T Nuclear Resonance Studies ...

  16. Electrical conductivity of (Mg,Fe)(Si,Al)O3 pv room temperature high temperature Ohta et al. (2010a) Ohta et al. (2010b) C. McCammon:High P,T Nuclear Resonance Studies ...

  17. Origin of conductivity drop – literature Reports of high-spin to low-spin transition in Fe3+: Theoretical Hsu et al. (2011) PRL Experimental Catalli et al. (2010) EPSL Catalli et al. (2011) EPSL Fujino et al. (2012) EPSL → conductivity drop is due to Fe3+ spin transition Ohta et al. (2010a) C. McCammon:High P,T Nuclear Resonance Studies ...

  18. Conductivity of (Mg,Fe)(Si,Al)O3pv Potapkin et al. in review Fe3+-rich Fe2+-rich Conductivity (S/m) P (GPa) C. McCammon:High P,T Nuclear Resonance Studies ...

  19. Origin of conductivity drop – our model Ohta et al. (2010a) Badro et al. (2004) McCammon et al. (2008) Conductivity drop is caused by a high-spin to intermediate-spin transition in Fe2+ C. McCammon:High P,T Nuclear Resonance Studies ...

  20. Lower mantle geophysical data Conductivity Kuvshinov and Olsen (2006) 900-1400 km Constable and Constable (2004) Tarits and Mandéa (2010) Velocity 1220 km from Tarits and Mandéa (2010) based on Becker and Boschi (2002) Tarits and Mandéa (2010) C. McCammon:High P,T Nuclear Resonance Studies ...

  21. Effect of Fe3+ on geophysical properties Fe3+-rich Fe2+-rich Conductivity (S/m) P (GPa) Potapkin et al. in review Glazyrin et al. in review ↑ Fe3+↑ Fe→ ↑ σ ↑ Fe3+↑ Fe → ↓VΦ C. McCammon:High P,T Nuclear Resonance Studies ...

  22. New constraints on lower mantle models Conductivity 900-1400 km Tarits and Mandéa (2010) Velocity 1220 km from Tarits and Mandéa (2010) based on Becker and Boschi (2002) C. McCammon:High P,T Nuclear Resonance Studies ...

  23. Summary • new method to investigate iron spin transitions • Fe2+ in silicate perovskite undergoes HS-IS and IS-LS transition in lower mantle • Fe3+in silicate perovskite undergoes no spin transitions in lower mantle • Conductivity drop can be explained by Fe2+ HS-IS transition • Properties of the spin transition may provide constraints on lower mantle modelling based on combined seismic and geomagnetic data C. McCammon:High P,T Nuclear Resonance Studies ...

  24. Acknowledgements BayerischesGeoinstitut K Glazyrin I Kupenko C Prescher R Sinmyo O Narygina I Kantor Special thanks: S Linhardt S Übelhack ESRF (Grenoble, France) A Chumakov A Kantor V Potapkin R Rüffer I Sergueev J-P Celse Kurchatov Institute (Moscow, Russia) G Smirnov S Popov Funded by: Bavarian Ministry PROCOPE/DAAD German Science Foundation (DFG) SPP1236 German Federal Ministry for Education and Research (BMBF) European Synchrotron Radiation Facility C. McCammon:High P,T Nuclear Resonance Studies ...

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