First Observation of Quenched Davemaoite to Ambient Conditions : Its Electron Diffraction Pattern

DOI zum Zitieren der Version auf EPub Bayreuth: https://doi.org/10.15495/EPub_UBT_00009135
URN to cite this document: urn:nbn:de:bvb:703-epub-9135-5

Title data

Miyajima, Nobuyoshi ; Wang, Lin ; Katsura, Tomoo:
First Observation of Quenched Davemaoite to Ambient Conditions : Its Electron Diffraction Pattern.
In: Geophysical Research Letters. Vol. 52 (2025) Issue 19 . - e2025GL115280.
ISSN 1944-8007
DOI der Verlagsversion: https://doi.org/10.1029/2025GL115280

	Format: PDF Name: Geophysical Research Letters - 2025 - Miyajima - First Observation of Quenched Davemaoite to Ambient Conditions Its.pdf Version: Published Version Available under License Creative Commons BY 4.0: Attribution
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Project information

Project title:	Project's official title Project's id Focused Ion Beam Scanning Electron Microscope (FIB-SEM) 257745926 Transmissionselektronenmikroskop 189856261 Open Access Publizieren No information
Project financing:	Deutsche Forschungsgemeinschaft

Abstract

Calcium-rich silicate perovskite (davemaoite) has been for the first time investigated at ambient pressure by electron diffraction in transmission electron microscopy. The obtained diffraction pattern in comparison to that of the coexisting Mg-rich silicate perovskite (bridgmanite) has revealed the cubic symmetry, Pm $øverline3$m, the lattice parameter a = 0.3561(4) nm and the volume V0 = 45.16(10) Å3 (27.19 cm3/mol), which is still larger molar volume than that of the coexisting bridgmanite (25.49 cm3/mol). With large volume difference davemaoite and bridgmanite coexist at equilibrium under the conditions at 40 GPa and 2,000°C. The nanometer-sized crystalline davemaoite (4.27 g/cm3) is mantled by the amorphous CaSiO3 (2.82 g/cm3). This core-mantle structure prevents amorphization of the unstable high-pressure mineral at the core due to a static pressure, 1.2(10) GPa generated by volume expansion on the transition at the mantle. This mechanism is the same as that of high-pressure minerals preserved in shocked meteorites.

Further data

Item Type:	Article in a journal
Keywords:	davemaoite; electron diffraction; static stress; transmission electron microscopy; bridgmanite; residual pressure
DDC Subjects:	500 Science > 550 Earth sciences, geology
Institutions of the University:	Research Institutions > Central research institutes > Bavarian Research Institute of Experimental Geochemistry and Geophysics - BGI Research Institutions Research Institutions > Central research institutes
Language:	English
Originates at UBT:	Yes
URN:	urn:nbn:de:bvb:703-epub-9135-5
Date Deposited:	17 Apr 2026 12:11
Last Modified:	17 Apr 2026 12:12
URI:	https://epub.uni-bayreuth.de/id/eprint/9135

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