Deformation microstructures of CaIrO3 post perovskite in a laser heated diamond anvil cell were examined using transmission electron microscopy. Under a high stress and strain rate in the deformation condition, a high density of the {110} twin domains were at first time observed in post perovskite structure, as well as [100] and [001] dislocations on the (010) plane. The exchange of the a-axis for the b-axes in the twin mechanism could reduce a stress in a single crystal at the beginning of the uniaxial compression. The {110} plane in post perovskite corresponds with that of the crystallographic preferred orientation that was previously reported in deformed MgSiO3 and MgGeO3 post perovskite in diamond anvil cells. This result implied that the formation of the twin domains could play an important role in CaIrO3 post perovskite deformation under high stress and strain rate conditions (e.g., deformation by diamond anvil cell).

Deformation Microtextures in CaIrO3 Post-Perovskite Under High Stress Conditions Using a Laser-Heated Diamond Anvil Cell. N.Miyajima, K.Niwa, F.Heidelbach, T.Yagi, K.Ohgushi: Journal of Physics - Conference Series, 2010, 215[1], 012097