Other
Scientific paper
Jan 1991
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991sci...251..410w&link_type=abstract
Science (ISSN 0036-8075), vol. 251, Jan. 25, 1991, p. 410-413.
Other
58
Earth Mantle, Equations Of State, Perovskites, Phase Transformations, Thermal Expansion, Chemical Composition, Crystal Structure, Temperature Effects, X Ray Diffraction
Scientific paper
Results from in situ X-ray diffraction experiments with a DIA-type cubic anvil apparatus (SAM 85) reveal that MgSiO3 perovskite transforms from the orthorhombic Pbnm symmetry to another perovskite-type structure above 600 K at pressures of 7.3 gigapascals; the apparent volume increase across the transition is 0.7 percent. Unit-cell volume increased linearly with temperature, both below and above the transition. These results indicate that the physical properties measured on the Pbnm phase should be used with great caution because they may not be applicable to the earth's lower mantle. A density analysis based on the new data yields an iron content of 10.4 wt pct for a pyrolite composition under conditions corresponding to the lower mantle. All current equation-of-state data are compatible with constant chemical composition in the upper and lower mantle; thus, these data imply that a chemically layered mantle is unnecessary, and whole-mantle convection is possible.
Ko Jaidong
Liebermann Robert C.
Liu Xing
Wang Yanbin
Weidner Donald J.
No associations
LandOfFree
Phase transition and thermal expansion of MgSiO3 perovskite does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Phase transition and thermal expansion of MgSiO3 perovskite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase transition and thermal expansion of MgSiO3 perovskite will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1896016