Elastic anisotropy of experimental analogues of perovskite and post-perovskite help to interpret D'' diversity
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Updated: May 1, 2026
Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance
Published on: February 27, 2017
Akira Yoneda1, Hiroshi Fukui2, Fang Xu1
1Institute for Study of the Earth's Interior, Okayama University, Misasa, Tottori 682-0193, Japan.
Abstract:
Recent studies show that the D'' layer, just above the Earth's core-mantle boundary, is composed of MgSiO3 post-perovskite and has significant lateral inhomogeneity. Here we consider the D'' diversity as related to the single-crystal elasticity of the post-perovskite phase. We measure the single-crystal elasticity of the perovskite Pbnm-CaIrO3 and post-perovskite Cmcm-CaIrO3 using inelastic X-ray scattering. These materials are structural analogues to same phases of MgSiO3. Our results show that Cmcm-CaIrO3 is much more elastically anisotropic than Pbnm-CaIrO3, which offers an explanation for the enigmatic seismic wave velocity jump at the D'' discontinuity. Considering the relation between lattice preferred orientation and seismic anisotropy in the D'' layer, we suggest that the c axis of post-perovskite MgSiO3 aligns vertically beneath the Circum-Pacific rim, and the b axis vertically beneath the Central Pacific.
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