HR: 1340h
AN: MR23B-0069    [Abstracts]
TI: Crystal Morphology and Dislocation Textures of the CaIrO₃ Phase -TEM Study of an Analogue of the Post-Perovskite Phase-
AU: * Miyajima, N
EM: nobuyoshi.miyajima@uni-bayreuth.de
AF: Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan, Kashiwa, 277-8581 Japan
AU: * Miyajima, N
EM: nobuyoshi.miyajima@uni-bayreuth.de
AF: Bayerisches Geoinstitut, Universitaet Bayreuth, D-95440 Bayreuth, Germany, Bayreuth, D-95440 Germany
AU: Ohgushi, K
EM: ohgushi@issp.u-tokyo.ac.jp
AF: Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan, Kashiwa, 277-8581 Japan
AU: Ichihara, M
EM: ichihara@issp.u-tokyo.ac.jp
AF: Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan, Kashiwa, 277-8581 Japan
AU: Yagi, T
EM: yagi@issp.u-tokyo.ac.jp
AF: Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan, Kashiwa, 277-8581 Japan
AU: Frost, D J
EM: Dan.Frost@Uni-Bayreuth.DE
AF: Bayerisches Geoinstitut, Universitaet Bayreuth, D-95440 Bayreuth, Germany, Bayreuth, D-95440 Germany
AU: Rubie, D C
EM: Dave.Rubie@uni-bayreuth.de
AF: Bayerisches Geoinstitut, Universitaet Bayreuth, D-95440 Bayreuth, Germany, Bayreuth, D-95440 Germany
AB: Polycrystalline of CaIrO₃ phase, synthesized in a multi-anvil apparatus at 4 GPa and 1473 K, contains several dislocations. The microstructures of the recovered material have been investigated using Transmission Electron Microscopy (TEM). The Burgers vectors of the dislocations were determined using the contrast method using Dark Field (DF) and Weak Beam Dark Field (WBDF) images. We found that the individual CaIrO₃ crystalline has the platy crystal habit elongated along the crystallographic a axis, which is the direction of the edge-shared octahedral chain. A <100> screw dislocation was activated in the CaIrO₃ phase during the synthesis experiments. The slip system might be identified as <100>{010, the most reasonable with the (010)- layered structure of IrO₆ octahedrons. For comparison, the dislocation texture of silicate perovskite has also been investigated. The dislocation texture appears to be different from one of CaIrO₃. The crystal morphology and dislocation textures of the CaIrO₃ phase could provide important constraints to discuss the deformation and the polarization anisotropy of the post-perovskite in the lowermost mantle.
DE: 1000 GEOCHEMISTRY
DE: 3600 MINERALOGY AND PETROLOGY
DE: 3900 MINERAL PHYSICS
DE: 7200 SEISMOLOGY
DE: 8100 TECTONOPHYSICS
SC: Mineral and Rock Physics [MR]
MN: Fall Meeting 2005