Publication in the European Journal of Mineralogy!

Publication in the European Journal of Mineralogy: Deformation of NaCoF3 perovskite and post-perovskite up to 30 GPa and 1013 K: implications for plastic deformation and transformation mechanismA new publication from a TIMEleSS student in the European Journal of Mineralogy : Deformation of NaCoF3 perovskite and post-perovskite up to 30 GPa and 1013 K: implications for plastic deformation and transformation mechanism.

Jeff Gay uses a resistively heated diamond anvil to study the plastic deformation and phase transformation mechanisms in NaCoF3. Under ambient pressure, NaCoF3. crystallizes in the perovskite structure, and later transforms to the post-perovskite. It is hence an excellent analogue to understand the physical properties of bridgmanite, the most abundant mineral on Earth, and dominant component of the Earth’s lower mantle between 660 and 2900 km depth.

These results from a collaboration between the Université de Lille, the University of Utah, University College London, and the PETRA III / DESY synchrotron source were published on 30 Sep 2021 in the European Journal of Mineralogy.

Full reference: J. P. Gay, L. Miyagi, S. Couper, C. Langrand, D. P. Dobson, H.-P. Liermann, S. Merkel, Deformation of NaCoF3 perovskite and post-perovskite up to 30 GPa and 1013 K: implications for plastic deformation and transformation mechanism, European Journal of Mineralogy, 33, 591–603 (2021), abstract [doi: 10.5194/ejm-33-591-2021].

Paper out in Nature Communications !

Kinetics and detectability of the bridgmanite to post-perovskite transformation in the Earth's D″ layerFirst  publication for the TIMEleSS team: Kinetics and detectability of the bridgmanite to post-perovskite transformation in the Earth’s D″ layer.

Bridgmanite is a magnesian-iron mineral ((Mg,Fe)SiO3) with a crystal structure that is not stable under ambient conditions. It forms about 660 kilometers below the surface of the Earth, and transforms to a new structure at even greater depth, approximately 2700 km depth, just above the Core-Mantle boundary.

During his PhD, C. Langrand, PhD student at the Université de Lille studied the kinetics of such transformation. It is fast on geological timescales: about 10 to 10,000 seconds, depending on pressure and temperature. Thanks to the collaborations in the TIMEleSS project, the authors realized that this includes the timescales of seismic waves. As such, seismic waves can trigger the transformation and, in turn, the transformation can amplify the seismic signal from D” seismic reflections.

These results from a collaboration between the Université de Lille, the université Clermont-Auvergne, the université de Lyon, the Westfälische Wilhelms-Universität, MünsterCNRS, and the PETRA III / DESY synchrotron source were published on 12 decembre 2019 in Nature Communications.

Full reference : C. Langrand, D. Andrault, S. Durand, Z. Konôpková, N. Hilairet, C. Thomas, S. Merkel, Kinetics and detectability of the bridgmanite to post-perovskite transformation in the Earth’s D″ layer, Nature Communications, 10, 5680 (2019) [doi: 10.1038/s41467-019-13482-x].