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Yin K, Belonoshko AB, Li Y, Lu X. Davemaoite as the mantle mineral with the highest melting temperature. SCIENCE ADVANCES 2023; 9:eadj2660. [PMID: 38055828 DOI: 10.1126/sciadv.adj2660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 11/07/2023] [Indexed: 12/08/2023]
Abstract
Knowledge of high-pressure melting curves of silicate minerals is critical for modeling the thermal-chemical evolution of rocky planets. However, the melting temperature of davemaoite, the third most abundant mineral in Earth's lower mantle, is still controversial. Here, we investigate the melting curves of two minerals, MgSiO3 bridgmanite and CaSiO3 davemaoite, under their stability field in the mantle by performing first-principles molecular dynamics simulations based on the density functional theory. The melting curve of bridgmanite is in excellent agreement with previous studies, confirming a general consensus on its melting temperature. However, we predict a much higher melting curve of davemaoite than almost all previous estimates. Melting temperature of davemaoite at the pressure of core-mantle boundary (~136 gigapascals) is about 7700(150) K, which is approximately 2000 K higher than that of bridgmanite. The ultrarefractory nature of davemaoite is critical to reconsider many models in the deep planetary interior, for instance, solidification of early magma ocean and geodynamical behavior of mantle rocks.
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Affiliation(s)
- Kun Yin
- Research Center for Planetary Science, College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China
| | - Anatoly B Belonoshko
- Frontiers Science Center for Critical Earth Material Cycling, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
- Condensed Matter Theory, Department of Physics, AlbaNova University Center, Royal Institute of Technology (KTH), 10691 Stockholm, Sweden
- National Research University Higher School of Economics, 123458 Moscow, Russia
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - Yonghui Li
- National Supercomputing Center in Chengdu, Chengdu 610299, China
| | - Xiancai Lu
- State Key Laboratory for Mineral Deposit Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
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Heinen BJ, Drewitt JWE, Walter MJ, Clapham C, Qin F, Kleppe AK, Lord OT. Internal resistive heating of non-metallic samples to 3000 K and >60 GPa in the diamond anvil cell. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:063904. [PMID: 34243587 DOI: 10.1063/5.0038917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 05/15/2021] [Indexed: 06/13/2023]
Abstract
High pressure-temperature experiments provide information on the phase diagrams and physical characteristics of matter at extreme conditions and offer a synthesis pathway for novel materials with useful properties. Experiments recreating the conditions of planetary interiors provide important constraints on the physical properties of constituent phases and are key to developing models of planetary processes and interpreting geophysical observations. The laser-heated diamond anvil cell (DAC) is currently the only technique capable of routinely accessing the Earth's lower-mantle geotherm for experiments on non-metallic samples, but large temperature uncertainties and poor temperature stability limit the accuracy of measured data and prohibits analyses requiring long acquisition times. We have developed a novel internal resistive heating (IRH) technique for the DAC and demonstrate stable heating of non-metallic samples up to 3000 K and 64 GPa, as confirmed by in situ synchrotron x-ray diffraction and simultaneous spectroradiometric temperature measurement. The temperature generated in our IRH-DAC can be precisely controlled and is extremely stable, with less than 20 K variation over several hours without any user intervention, resulting in temperature uncertainties an order of magnitude smaller than those in typical laser-heating experiments. Our IRH-DAC design, with its simple geometry, provides a new and highly accessible tool for investigating materials at extreme conditions. It is well suited for the rapid collection of high-resolution P-V-T data, precise demarcation of phase boundaries, and experiments requiring long acquisition times at high temperature. Our IRH technique is ideally placed to exploit the move toward coherent nano-focused x-ray beams at next-generation synchrotron sources.
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Affiliation(s)
- Benedict J Heinen
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS81RJ, United Kingdom
| | - James W E Drewitt
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS81RJ, United Kingdom
| | - Michael J Walter
- Earth and Planets Laboratory, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USA
| | - Charles Clapham
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS81RJ, United Kingdom
| | - Fei Qin
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS81RJ, United Kingdom
| | - Annette K Kleppe
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX110DE, United Kingdom
| | - Oliver T Lord
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS81RJ, United Kingdom
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