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Title: Deep‐Learning‐Based Prediction of the Tetragonal → Cubic Transition in Davemaoite
Abstract Davemaoite, that is, CaSiO3perovskite (CaPv), is the third most abundant phase in the lower mantle and exhibits a tetragonal‐cubic phase transition at high pressures and temperatures. The phase boundary in CaPv has recently been proposed to be close to the cold slab adiabat and cause mid‐mantle seismic wave speed anomalies (Thomson et al., 2019,https://doi.org/10.1038/s41586‐019‐1483‐x). This study utilized accurate deep‐learning‐based simulations and thermodynamic integration techniques to compute free energies at temperatures ranging from 300 to 3,000 K and pressures up to 130 GPa. Our results indicate that CaPv exhibits a single cubic phase throughout lower‐mantle conditions. This suggests that the phase diagram proposed by Thomson et al. requires revision, and mid‐mantle seismic anomalies are likely attributable to other mechanisms.  more » « less
Award ID(s):
2000850
PAR ID:
10527872
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
American Geophysical Union
Date Published:
Journal Name:
Geophysical Research Letters
Edition / Version:
1
Volume:
51
Issue:
12
ISSN:
0094-8276
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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