title: Elasticity of MgSiO3 in the Perovskite Structure.
abstract: The single-crystal elastic moduli of MgSiO(3) in the perovskite structure, the high-pressure polymorph of MgSiO(3) pyroxene, have been determined. The data indicate that a mantle with either pyrolite or pyroxene stoichiometry is compatible with the seismic models appropriate to the earth's lower mantle, provided that the shear modulus of MgSiO(3) perovskite exhibits a strong negative temperature derivative. Such a temperature derivative falls outside of the range expected for a well-behaved refractory ceramic and could result if the pressure-temperature regime of the earth's lower mantle is near that required for a ferroelastic phase transformation of the perovskite phase.
authors.forename: A
authors.initials: A
authors.lastname: Yeganeh-Haeri
authors.forename: D J
authors.initials: DJ
authors.lastname: Weidner
authors.forename: E
authors.initials: E
authors.lastname: Ito