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Statut |
Confirmé |
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Série |
SEM-BESSON |
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Domaines |
cond-mat |
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Date |
Jeudi 13 Novembre 2008 |
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Heure |
14:30 |
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Institut |
IMPMC |
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Salle |
Salle de conférence, Bâtiment 15, 140 rue de Lourmel, 75015 Paris |
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Nom de l'orateur |
Pr. Ito |
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Prenom de l'orateur |
Eiji |
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Addresse email de l'orateur |
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Institution de l'orateur |
Institute for Study of the Earth’s Interior, Okayama University, Japan |
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Titre |
In situ x-ray experiments using a kawai-cell with sintered diamond cubes: the post-perovskite transformation in mggeo3 |
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Résumé |
High pressure generation was tried by using the Kawai-cell equipped with sintered diamond cubes and the synchrotron radiation at SPring-8. Pressure determination was based on the Anderson et al’s [1989] Au scale. The maximum attainable pressure reached 85 GPa at 300 K and 89 GPa at 1000 K. We investigated the perovskite (Pv)–postperovskite (CaIrO3 type, PPv) transformation in MgGeO3 up to 74 GPa and 2173 K by in situ X-ray diffraction method. Transformation from Pv to PPv was observed at higher than ca. 63 GPa and 1300 K and we determined its phase boundary. A “tradeoff” among phase boundary slope dP/dT for the transformation, geotherm, and thickness of PPv layer in the lowermost mantle [van der Hilst et al., 2007] suggests that if our MgGeO3 slope of 5MPa/K were available, the PPv layer would be most suppressed and so called PPv lens might not form. However, adoption of other pressure scale, e.g. Tsuchiya’s [2003] Au scale, our phase boundary shifts toward higher pressure by 3.5 GPa with a slightly larger dP/dT slope. |
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Numéro de preprint arXiv |
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