title: Effect of cation substitution on bridgmanite elasticity: A key to interpret seismic anomalies in the lower mantle.
abstract: Seismological observations show that, in some regions of the lower mantle, an increase in bulk sound velocity, interestingly, occurs in the same volume where there is a decrease in shear velocity. We show that this anti-correlated behavior occurs on cation substitution in bridgmanite by making single crystal elasticity measurements of MgSiO3 and (Mg,Fe,Al)(Si,Al)O3 using inelastic x-ray scattering in the ambient conditions. Cation substitution of ferrous iron and aluminum may explain large low shear velocity provinces in the lower mantle.
authors.affiliation: Center for Novel Material Science under Multi-Extreme Conditions, Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Hyogo 678-1297, Japan.|Materials Dynamics Laboratory, RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo, Hyogo 689-5148, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukui
authors.affiliation: Institute for Planetary Materials, Okayama University, 827 Yamada, Misasa, Tottori 682-0193, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yoneda
authors.affiliation: Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nakatsuka
authors.affiliation: Institute for Planetary Materials, Okayama University, 827 Yamada, Misasa, Tottori 682-0193, Japan.
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Tsujino
authors.affiliation: Graduate School of Science, Tohoku University, 6-3 Aramaki, Aoba, Sendai, Miyagi 980-8578, Japan.|Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki, Aoba, Sendai, Miyagi 980-8578, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kamada
authors.affiliation: Graduate School of Science, Tohoku University, 6-3 Aramaki, Aoba, Sendai, Miyagi 980-8578, Japan.|V. S. Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.
authors.forename: Eiji
authors.initials: E
authors.lastname: Ohtani
authors.affiliation: V. S. Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.
authors.forename: Anton
authors.initials: A
authors.lastname: Shatskiy
authors.affiliation: Research and Utilization Division, Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 689-5198, Japan.
authors.forename: Naohisa
authors.initials: N
authors.lastname: Hirao
authors.affiliation: Research and Utilization Division, Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 689-5198, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsutsui
authors.affiliation: Materials Dynamics Laboratory, RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo, Hyogo 689-5148, Japan.|Research and Utilization Division, Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 689-5198, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uchiyama
authors.affiliation: Materials Dynamics Laboratory, RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo, Hyogo 689-5148, Japan.|Research and Utilization Division, Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 689-5198, Japan.
authors.forename: Alfred Q R
authors.initials: AQ
authors.lastname: Baron