title: Evidence for a phase transition in silicate melt at extreme pressure and temperature conditions.
abstract: Laser-driven shock compression experiments reveal the presence of a phase transition in MgSiO(3) over the pressure-temperature range 300-400 GPa and 10 000-16 000 K, with a positive Clapeyron slope and a volume change of ∼6.3 (±2.0) percent. The observations are most readily interpreted as an abrupt liquid-liquid transition in a silicate composition representative of terrestrial planetary mantles, implying potentially significant consequences for the thermal-chemical evolution of extrasolar planetary interiors. In addition, the present results extend the Hugoniot equation of state of MgSiO(3) single crystal and glass to 950 GPa.
authors.affiliation: Department of Earth and Planetary Science, University of California, Berkeley, California 94720-4767, USA.
authors.forename: D K
authors.initials: DK
authors.lastname: Spaulding
authors.forename: R S
authors.initials: RS
authors.lastname: McWilliams
authors.forename: R
authors.initials: R
authors.lastname: Jeanloz
authors.forename: J H
authors.initials: JH
authors.lastname: Eggert
authors.forename: P M
authors.initials: PM
authors.lastname: Celliers
authors.forename: D G
authors.initials: DG
authors.lastname: Hicks
authors.forename: G W
authors.initials: GW
authors.lastname: Collins
authors.forename: R F
authors.initials: RF
authors.lastname: Smith