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Elasticity of post‐perovskite MgSiO 3
Author(s) -
Tsuchiya Taku,
Tsuchiya Jun,
Umemoto Koichiro,
Wentzcovitch Renata M.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl020278
Subject(s) - anisotropy , transverse isotropy , shear modulus , bulk modulus , isotropy , perovskite (structure) , shear (geology) , materials science , mineralogy , elastic modulus , elasticity (physics) , phase (matter) , post perovskite , geology , lattice constant , condensed matter physics , crystallography , geophysics , composite material , diffraction , optics , physics , chemistry , mantle (geology) , quantum mechanics
We have determined by first principles the athermal elastic constant tensor, single crystal and aggregated acoustic velocities, and anisotropy of the recently discovered post‐perovskite MgSiO 3 polymorph. This phase may be the most abundant mineral in the D″ region. We find that the post‐perovskite phase has similar bulk modulus and larger shear modulus than perovskite at relevant pressures. This phase is remarkably anisotropic. Analyses of horizontal shear wave splittings in transversely isotropic aggregates indicate that diverse lattice preferred orientations could produce large variation in anisotropy consistent with seismic observations in D″.