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Diamond MR, Shen G, Popov DY, Park C, Jacobsen SD, Jeanloz R. Electron Density Changes across the Pressure-Induced Iron Spin Transition. PHYSICAL REVIEW LETTERS 2022; 129:025701. [PMID: 35867445 DOI: 10.1103/physrevlett.129.025701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 08/02/2021] [Accepted: 12/14/2021] [Indexed: 06/15/2023]
Abstract
High-pressure single-crystal x-ray diffraction is used to experimentally map the electron-density distribution changes in (Fe,Mg)O as ferrous iron undergoes a pressure-induced transition from high- to low-spin states. As the bulk density and elasticity of magnesiowüstite-one of the dominant mineral phases of Earth's mantle-are affected by this electronic transition, our results have applications to geophysics as well as to validating first-principles calculations. The observed changes in diffraction intensities indicate a spin-transition-induced change in orbital occupancies of the Fe ion in general accord with crystal-field theory, illustrating the use of electron density measurements for characterizing high-pressure d-block chemistry and motivating further studies characterizing chemical bonding under pressure.
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Affiliation(s)
- Matthew R Diamond
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
| | - Guoyin Shen
- HPCAT, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Dmitry Y Popov
- HPCAT, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Changyong Park
- HPCAT, X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Steven D Jacobsen
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, Illinois 60208, USA
| | - Raymond Jeanloz
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
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2
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Davis AH, Solomatova NV, Campbell AJ, Caracas R. The Speciation and Coordination of a Deep Earth Carbonate-Silicate-Metal Melt. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2022; 127:e2021JB023314. [PMID: 35866035 PMCID: PMC9286813 DOI: 10.1029/2021jb023314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 02/05/2022] [Accepted: 03/07/2022] [Indexed: 06/15/2023]
Abstract
Ab initio molecular dynamics calculations on a carbonate-silicate-metal melt were performed to study speciation and coordination changes as a function of pressure and temperature. We examine in detail the bond abundances of specific element pairs and the distribution of coordination environments over conditions spanning Earth's present-day mantle. Average coordination numbers increase continuously from 4 to 8 for Fe and Mg, from 4 to 6 for Si, and from 2 to 4 for C from 1 to 148 GPa (4,000 K). Speciation across all pressure and temperature conditions is complex due to the unusual bonding of carbon. With the increasing pressure, C-C and C-Fe bonding increase significantly, resulting in the formation of carbon polymers, C-Fe clusters, and the loss of carbonate groups. The increased bonding of carbon with elements other than oxygen indicates that carbon begins to replace oxygen as an anion in the melt network. We evaluate our results in the context of diamond formation and of metal-silicate partitioning behavior of carbon. Our work has implications for properties of carbon and metal-bearing silicate melts, such as viscosity, electrical conductivity, and reactivity with surrounding phases.
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Affiliation(s)
- A. H. Davis
- Department of the Geophysical SciencesUniversity of ChicagoChicagoILUSA
| | - N. V. Solomatova
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
| | - A. J. Campbell
- Department of the Geophysical SciencesUniversity of ChicagoChicagoILUSA
| | - R. Caracas
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
- The Center for Earth Evolution and Dynamics (CEED)University of OsloOsloNorway
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3
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Effects of iron spin transition on the electronic structure, thermal expansivity and lattice thermal conductivity of ferropericlase: a first principles study. Sci Rep 2019; 9:4172. [PMID: 30862901 PMCID: PMC6414721 DOI: 10.1038/s41598-019-40454-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 02/14/2019] [Indexed: 11/08/2022] Open
Abstract
The effects of the spin transition on the electronic structure, thermal expansivity and lattice thermal conductivity of ferropericlase are studied by first principles calculations at high pressures. The electronic structures indicate that ferropericlase is an insulator for high-spin and low-spin states. Combined with the quasiharmonic approximation, our calculations show that the thermal expansivity is larger in the high-spin state than in the low-spin state at ambient pressure, while the magnitude exhibits a crossover between high-spin and low-spin with increasing pressure. The calculated lattice thermal conductivity exhibits a drastic reduction upon the inclusion of ferrous iron, which is consistent with previous experimental studies. However, a subsequent enhancement in the thermal conductivity is obtained, which is associated with the spin transition. Mechanisms are discussed for the variation in thermal conductivity by the inclusion of ferrous iron and the spin transition.
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4
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Yang K, Wang X, Zhang J, Cheng Y, Zhang C, Zeng Z, Lin H. Effects of vacancy defects on Fe properties incorporated in MgO. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:295701. [PMID: 29873304 DOI: 10.1088/1361-648x/aacabd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Distributions of Fe in MgO containing Mg vacancy, O vacancy, and Schottky defect are investigated based on the density functional theory (DFT). Our results show that since Mg vacancy will remove electrons from MgO, Fe tends to get close to Mg vacancy but far from O vacancy. The Mg vacancy can decrease the magnetic moment of iron and change its valence state from 2+ to 3+, which leads to ~5% decrease of Fe-O bond length comparable to the effect of 30 GPa external pressure. Furthermore, iron incorporation can increase the Schottky defect concentration of MgO especially in the environment of the Earth's lower mantle, where ~20 mol% Fe-bearing MgO locates at extreme high temperature conditions.
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Affiliation(s)
- Kaishuai Yang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China. University of Science and Technology of China, Hefei 230026, People's Republic of China. Beijing Computational Science Research Center, Beijing 100084, People's Republic of China
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Cheng Y, Wang X, Zhang J, Yang K, Zhang C, Zeng Z, Lin H. Investigation of iron spin crossover pressure in Fe-bearing MgO using hybrid functional. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:155403. [PMID: 29512517 DOI: 10.1088/1361-648x/aab4b5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Pressure-induced spin crossover behaviors of Fe-bearing MgO were widely investigated by using an LDA + U functional for describing the strongly correlated Fe-O bonding. Moreover, the simulated spin crossover pressures depend on the applied U values, which are sensitive to environments and parameters. In this work, the spin crossover pressures of (Mg1-x ,Fe x )O are investigated by using the hybrid functional with a uniform parameter. Our results indicate that the spin crossover pressures increase with increasing iron concentration. For example, the spin crossover pressure of (Mg0.03125,Fe0.96875)O and FeO was 56 GPa and 127 GPa, respectively. The calculated crossover pressures agreed well with the experimental observations. Therefore, the hybrid functional should be an effective method for describing the pressure-induced spin crossover behaviors in transition metal oxides.
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Affiliation(s)
- Ya Cheng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China. University of Science and Technology of China, Hefei 230026, People's Republic of China
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6
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Deng J, Lee KKM. Viscosity jump in the lower mantle inferred from melting curves of ferropericlase. Nat Commun 2017; 8:1997. [PMID: 29222478 PMCID: PMC5722891 DOI: 10.1038/s41467-017-02263-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 11/16/2017] [Indexed: 11/09/2022] Open
Abstract
Convection provides the mechanism behind plate tectonics, which allows oceanic lithosphere to be subducted into the mantle as "slabs" and new rock to be generated by volcanism. Stagnation of subducting slabs and deflection of rising plumes in Earth's shallow lower mantle have been suggested to result from a viscosity increase at those depths. However, the mechanism for this increase remains elusive. Here, we examine the melting behavior in the MgO-FeO binary system at high pressures using the laser-heated diamond-anvil cell and show that the liquidus and solidus of (Mg x Fe1-x )O ferropericlase (x = ~0.52-0.98), exhibit a local maximum at ~40 GPa, likely caused by the spin transition of iron. We calculate the relative viscosity profiles of ferropericlase using homologous temperature scaling and find that viscosity increases 10-100 times from ~750 km to ~1000-1250 km, with a smaller decrease at deeper depths, pointing to a single mechanism for slab stagnation and plume deflection.
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Affiliation(s)
- Jie Deng
- Department of Geology and Geophysics, Yale University, New Haven, CT, 06511, USA.
| | - Kanani K M Lee
- Department of Geology and Geophysics, Yale University, New Haven, CT, 06511, USA
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7
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Diamond formation in the deep lower mantle: a high-pressure reaction of MgCO 3 and SiO 2. Sci Rep 2017; 7:40602. [PMID: 28084421 PMCID: PMC5233982 DOI: 10.1038/srep40602] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/07/2016] [Indexed: 11/29/2022] Open
Abstract
Diamond is an evidence for carbon existing in the deep Earth. Some diamonds are considered to have originated at various depth ranges from the mantle transition zone to the lower mantle. These diamonds are expected to carry significant information about the deep Earth. Here, we determined the phase relations in the MgCO3-SiO2 system up to 152 GPa and 3,100 K using a double sided laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction. MgCO3 transforms from magnesite to the high-pressure polymorph of MgCO3, phase II, above 80 GPa. A reaction between MgCO3 phase II and SiO2 (CaCl2-type SiO2 or seifertite) to form diamond and MgSiO3 (bridgmanite or post-perovsktite) was identified in the deep lower mantle conditions. These observations suggested that the reaction of the MgCO3 phase II with SiO2 causes formation of super-deep diamond in cold slabs descending into the deep lower mantle.
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8
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Shen G, Mao HK. High-pressure studies with x-rays using diamond anvil cells. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:016101. [PMID: 27873767 DOI: 10.1088/1361-6633/80/1/016101] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Pressure profoundly alters all states of matter. The symbiotic development of ultrahigh-pressure diamond anvil cells, to compress samples to sustainable multi-megabar pressures; and synchrotron x-ray techniques, to probe materials' properties in situ, has enabled the exploration of rich high-pressure (HP) science. In this article, we first introduce the essential concept of diamond anvil cell technology, together with recent developments and its integration with other extreme environments. We then provide an overview of the latest developments in HP synchrotron techniques, their applications, and current problems, followed by a discussion of HP scientific studies using x-rays in the key multidisciplinary fields. These HP studies include: HP x-ray emission spectroscopy, which provides information on the filled electronic states of HP samples; HP x-ray Raman spectroscopy, which probes the HP chemical bonding changes of light elements; HP electronic inelastic x-ray scattering spectroscopy, which accesses high energy electronic phenomena, including electronic band structure, Fermi surface, excitons, plasmons, and their dispersions; HP resonant inelastic x-ray scattering spectroscopy, which probes shallow core excitations, multiplet structures, and spin-resolved electronic structure; HP nuclear resonant x-ray spectroscopy, which provides phonon densities of state and time-resolved Mössbauer information; HP x-ray imaging, which provides information on hierarchical structures, dynamic processes, and internal strains; HP x-ray diffraction, which determines the fundamental structures and densities of single-crystal, polycrystalline, nanocrystalline, and non-crystalline materials; and HP radial x-ray diffraction, which yields deviatoric, elastic and rheological information. Integrating these tools with hydrostatic or uniaxial pressure media, laser and resistive heating, and cryogenic cooling, has enabled investigations of the structural, vibrational, electronic, and magnetic properties of materials over a wide range of pressure-temperature conditions.
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Affiliation(s)
- Guoyin Shen
- Geophysical Laboratory, Carnegie Institution of Washington, Washington DC, USA
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9
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Holmström E, Stixrude L. Spin crossover in ferropericlase from first-principles molecular dynamics. PHYSICAL REVIEW LETTERS 2015; 114:117202. [PMID: 25839305 DOI: 10.1103/physrevlett.114.117202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Indexed: 06/04/2023]
Abstract
Ferropericlase, (Mg,Fe)O, is the second-most abundant mineral of Earth's lower mantle. With increasing pressure, the Fe ions in the material begin to collapse from a magnetic to nonmagnetic spin state. We present a finite-temperature first-principles phase diagram of this spin crossover, finding a broad pressure range with coexisting magnetic and nonmagnetic ions due to favorable enthalpy of mixing of the two. Furthermore, we find the electrical conductivity of the mineral to reach semimetallic values inside Earth.
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Affiliation(s)
- E Holmström
- Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - L Stixrude
- Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom
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10
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Šimko F, Rakhmatullin A, Bessada C, Boča M. MAS NMR study of the solidified cryolite systems with FeO addition. J Fluor Chem 2014. [DOI: 10.1016/j.jfluchem.2014.06.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Wu Z, Justo JF, Wentzcovitch RM. Elastic anomalies in a spin-crossover system: ferropericlase at lower mantle conditions. PHYSICAL REVIEW LETTERS 2013; 110:228501. [PMID: 23767753 DOI: 10.1103/physrevlett.110.228501] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Indexed: 06/02/2023]
Abstract
The discovery of a pressure induced iron-related spin crossover in Mg((1-x))Fe(x)O ferropericlase (Fp) and Mg-silicate perovskite, the major phases of Earth's lower mantle, has raised new questions about mantle properties which are of central importance to seismology. Despite extensive experimental work on the anomalous elasticity of Fp throughout the crossover, inconsistencies reported in the literature are still unexplained. Here we introduce a formulation for thermoelasticity of spin crossover systems, apply it to Fp by combining it with predictive first principles density-functional theory with on-site repulsion parameter U calculations, and contrast results with available data on samples with various iron concentrations. We explain why the shear modulus of Fp should not soften along the crossover, as observed in some experiments, predict its velocities at lower mantle conditions, and show the importance of constraining the elastic properties of minerals without extrapolations for analyses of the thermochemical state of this region.
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Affiliation(s)
- Zhongqing Wu
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
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12
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Quantum critical point and spin fluctuations in lower-mantle ferropericlase. Proc Natl Acad Sci U S A 2013; 110:7142-7. [PMID: 23589892 DOI: 10.1073/pnas.1304827110] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ferropericlase [(Mg,Fe)O] is one of the most abundant minerals of the earth's lower mantle. The high-spin (HS) to low-spin (LS) transition in the Fe(2+) ions may dramatically alter the physical and chemical properties of (Mg,Fe)O in the deep mantle. To understand the effects of compression on the ground electronic state of iron, electronic and magnetic states of Fe(2+) in (Mg0.75Fe0.25)O have been investigated using transmission and synchrotron Mössbauer spectroscopy at high pressures and low temperatures (down to 5 K). Our results show that the ground electronic state of Fe(2+) at the critical pressure Pc of the spin transition close to T = 0 is governed by a quantum critical point (T = 0, P = P(c)) at which the energy required for the fluctuation between HS and LS states is zero. Analysis of the data gives P(c) = 55 GPa. Thermal excitation within the HS or LS states (T > 0 K) is expected to strongly influence the magnetic as well as physical properties of ferropericlase. Multielectron theoretical calculations show that the existence of the quantum critical point at temperatures approaching zero affects not only physical properties of ferropericlase at low temperatures but also its properties at P-T of the earth's lower mantle.
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13
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Gütlich P, Gaspar AB, Garcia Y. Spin state switching in iron coordination compounds. Beilstein J Org Chem 2013; 9:342-91. [PMID: 23504535 PMCID: PMC3596041 DOI: 10.3762/bjoc.9.39] [Citation(s) in RCA: 477] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 01/18/2013] [Indexed: 11/29/2022] Open
Abstract
The article deals with coordination compounds of iron(II) that may exhibit thermally induced spin transition, known as spin crossover, depending on the nature of the coordinating ligand sphere. Spin transition in such compounds also occurs under pressure and irradiation with light. The spin states involved have different magnetic and optical properties suitable for their detection and characterization. Spin crossover compounds, though known for more than eight decades, have become most attractive in recent years and are extensively studied by chemists and physicists. The switching properties make such materials potential candidates for practical applications in thermal and pressure sensors as well as optical devices. The article begins with a brief description of the principle of molecular spin state switching using simple concepts of ligand field theory. Conditions to be fulfilled in order to observe spin crossover will be explained and general remarks regarding the chemical nature that is important for the occurrence of spin crossover will be made. A subsequent section describes the molecular consequences of spin crossover and the variety of physical techniques usually applied for their characterization. The effects of light irradiation (LIESST) and application of pressure are subjects of two separate sections. The major part of this account concentrates on selected spin crossover compounds of iron(II), with particular emphasis on the chemical and physical influences on the spin crossover behavior. The vast variety of compounds exhibiting this fascinating switching phenomenon encompasses mono-, oligo- and polynuclear iron(II) complexes and cages, polymeric 1D, 2D and 3D systems, nanomaterials, and polyfunctional materials that combine spin crossover with another physical or chemical property.
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Affiliation(s)
- Philipp Gütlich
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität, Staudingerweg 9, 55099 Mainz, Germany
| | - Ana B Gaspar
- Institut de Ciència Molecular (ICMOL)/Departament de Química Inorgànica, Universitat de València, Edifici de Instituts de Paterna, Apartat de Correus 22085, 46071 València, Spain
| | - Yann Garcia
- Institute of Condensed Matter and Nanosciences, MOST – Inorganic Chemistry, Université Catholique de Louvain, Place L. Pasteur 1, 1348 Louvain la Neuve, Belgium
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Chen B, Jackson JM, Sturhahn W, Zhang D, Zhao J, Wicks JK, Murphy CA. Spin crossover equation of state and sound velocities of (Mg0.65Fe0.35)O ferropericlase to 140 GPa. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jb009162] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Ju S, Cai TY, Lu HS, Gong CD. Pressure-Induced Crystal Structure and Spin-State Transitions in Magnetite (Fe3O4). J Am Chem Soc 2012; 134:13780-6. [DOI: 10.1021/ja305167h] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sheng Ju
- Department
of Physics and Jiangsu
Key Laboratory of Thin Films, Soochow University, Suzhou 215006, P. R. China
| | - Tian-Yi Cai
- Department
of Physics and Jiangsu
Key Laboratory of Thin Films, Soochow University, Suzhou 215006, P. R. China
| | - Hai-Shuang Lu
- Department
of Physics and Jiangsu
Key Laboratory of Thin Films, Soochow University, Suzhou 215006, P. R. China
| | - Chang-De Gong
- Center for Statistical and Theoretical
Condensed Matter Physics and Department of Physics, Zhejiang Normal University, Jinhua 321004, P. R. China
- National Laboratory of Solid State
Microstructure and Department of Physics, Nanjing University, Nanjing 210093, P. R. China
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16
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Shahnas MH, Peltier WR, Wu Z, Wentzcovitch R. The high-pressure electronic spin transition in iron: Potential impacts upon mantle mixing. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jb007965] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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17
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Yoshino T, Ito E, Katsura T, Yamazaki D, Shan S, Guo X, Nishi M, Higo Y, Funakoshi KI. Effect of iron content on electrical conductivity of ferropericlase with implications for the spin transition pressure. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jb007801] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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18
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Anomalous compressibility of ferropericlase throughout the iron spin cross-over. Proc Natl Acad Sci U S A 2009; 106:8447-52. [PMID: 19439661 DOI: 10.1073/pnas.0812150106] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The thermoelastic properties of ferropericlase Mg(1-x)Fe(x)O (x = 0.1875) throughout the iron high-to-low spin cross-over have been investigated by first principles at Earth's lower mantle conditions. This cross-over has important consequences for elasticity such as an anomalous bulk modulus (K(S)) reduction. At room temperature the anomaly is somewhat sharp in pressure but broadens with increasing temperature. Along a typical geotherm it occurs across most of the lower mantle with a more significant K(S) reduction at approximately 1,400-1,600 km depth. This anomaly might also cause a reduction in the effective activation energy for diffusion creep and lead to a viscosity minimum in the mid-lower mantle, in apparent agreement with results from inversion of data related with mantle convection and postglacial rebound.
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19
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Marquardt H, Speziale S, Reichmann HJ, Frost DJ, Schilling FR, Garnero EJ. Elastic Shear Anisotropy of Ferropericlase in Earth's Lower Mantle. Science 2009; 324:224-6. [DOI: 10.1126/science.1169365] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Hauke Marquardt
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany
- School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287, USA
| | - Sergio Speziale
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany
- School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287, USA
| | - Hans J. Reichmann
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany
- School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287, USA
| | - Daniel J. Frost
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany
- School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287, USA
| | - Frank R. Schilling
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany
- School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287, USA
| | - Edward J. Garnero
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Bayerisches Geoinstitut, Universität Bayreuth, 95440 Bayreuth, Germany
- School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287, USA
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Sinmyo R, Hirose K, Nishio-Hamane D, Seto Y, Fujino K, Sata N, Ohishi Y. Partitioning of iron between perovskite/postperovskite and ferropericlase in the lower mantle. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008jb005730] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Rouquette J, Kantor I, McCammon CA, Dmitriev V, Dubrovinsky LS. High-Pressure Studies of (Mg0.9Fe0.1)2SiO4 Olivine Using Raman Spectroscopy, X-ray Diffraction, and Mössbauer Spectroscopy. Inorg Chem 2008; 47:2668-73. [PMID: 18318490 DOI: 10.1021/ic701983w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. Rouquette
- Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany, and European Radiation Synchrotron Facility (ESRF), Swiss-Norwegian Beam Lines (SNBL), BP220 38047 Grenoble CEDEX 9, France
| | - I. Kantor
- Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany, and European Radiation Synchrotron Facility (ESRF), Swiss-Norwegian Beam Lines (SNBL), BP220 38047 Grenoble CEDEX 9, France
| | - C. A. McCammon
- Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany, and European Radiation Synchrotron Facility (ESRF), Swiss-Norwegian Beam Lines (SNBL), BP220 38047 Grenoble CEDEX 9, France
| | - V. Dmitriev
- Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany, and European Radiation Synchrotron Facility (ESRF), Swiss-Norwegian Beam Lines (SNBL), BP220 38047 Grenoble CEDEX 9, France
| | - L. S. Dubrovinsky
- Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany, and European Radiation Synchrotron Facility (ESRF), Swiss-Norwegian Beam Lines (SNBL), BP220 38047 Grenoble CEDEX 9, France
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22
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Crowhurst JC, Brown JM, Goncharov AF, Jacobsen SD. Elasticity of (Mg,Fe)O Through the Spin Transition of Iron in the Lower Mantle. Science 2008; 319:451-3. [DOI: 10.1126/science.1149606] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- J. C. Crowhurst
- Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory (LLNL), Livermore, CA 94550, USA
- Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL 60208, USA
| | - J. M. Brown
- Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory (LLNL), Livermore, CA 94550, USA
- Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL 60208, USA
| | - A. F. Goncharov
- Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory (LLNL), Livermore, CA 94550, USA
- Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL 60208, USA
| | - S. D. Jacobsen
- Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory (LLNL), Livermore, CA 94550, USA
- Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL 60208, USA
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23
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Speziale S, Lee VE, Clark SM, Lin JF, Pasternak MP, Jeanloz R. Effects of Fe spin transition on the elasticity of (Mg, Fe)O magnesiowüstites and implications for the seismological properties of the Earth's lower mantle. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004730] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ohta K, Hirose K, Onoda S, Shimizu K. The effect of iron spin transition on electrical conductivity of (Mg,Fe)O magnesiowüstite. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2007; 83:97-100. [PMID: 24019587 PMCID: PMC3756880 DOI: 10.2183/pjab.83.97] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Accepted: 02/26/2007] [Indexed: 06/02/2023]
Abstract
We measured the electrical conductivity of Mg0.81Fe0.19O magnesiowüstite, one of the important minerals comprising Earth's lower mantle, at high pressures up to 135 GPa and 300 K in a diamond-anvil cell (DAC). The results demonstrate that the electrical conductivity increases with increasing pressure to about 60 GPa and exhibits anomalous behavior at higher pressures; it conversely decreases to around 80 GPa and again increases very mildly with pressure. These observed changes may be explained by the high-spin to low-spin transition of iron in magnesiowüstite that was previously reported to occur in a similar pressure range. A very small pressure effect on the electrical conductivity above 80 GPa suggests that a dominant conduction mechanism changes by this electronic spin transition. The electrical conductivity below 2000-km depth in the mantle may be much smaller than previously thought, since the spin transition takes place also in (Mg,Fe)SiO3 perovskite.
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Affiliation(s)
- Kenji Ohta
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo,
Japan
| | - Kei Hirose
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo,
Japan
| | - Suzue Onoda
- Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Osaka,
Japan
| | - Katsuya Shimizu
- Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Osaka,
Japan
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25
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Electronic transitions and spin states in the lower mantle. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/174gm06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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26
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Goncharov AF, Struzhkin VV, Jacobsen SD. Reduced Radiative Conductivity of Low-Spin (Mg,Fe)O in the Lower Mantle. Science 2006; 312:1205-8. [PMID: 16728639 DOI: 10.1126/science.1125622] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Optical absorption spectra have been measured at pressures up to 80 gigapascals (GPa) for the lower-mantle oxide magnesiowüstite (Mg,Fe)O. Upon reaching the high-spin to low-spin transition of Fe2+ at about 60 GPa, we observed enhanced absorption in the mid- and near-infrared spectral range, whereas absorption in the visible-ultraviolet was reduced. The observed changes in absorption are in contrast to prediction and are attributed to d-d orbital charge transfer in the Fe2+ ion. The results indicate that low-spin (Mg,Fe)O will exhibit lower radiative thermal conductivity than high-spin (Mg,Fe)O, which needs to be considered in future geodynamic models of convection and plume stabilization in the lower mantle.
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Affiliation(s)
- Alexander F Goncharov
- Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, DC 20015, USA.
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Tsuchiya T, Wentzcovitch RM, da Silva CRS, de Gironcoli S. Spin transition in magnesiowüstite in earth's lower mantle. PHYSICAL REVIEW LETTERS 2006; 96:198501. [PMID: 16803146 DOI: 10.1103/physrevlett.96.198501] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Indexed: 05/10/2023]
Abstract
Iron in the major lower mantle (LM) minerals undergoes a high spin (HS) to low spin (LS) transition at relevant pressures (23-135 GPa). Previous failures of standard first principles approaches to describe this phenomenon have hindered its investigation and the clarification of important consequences. Using a rotationally invariant formulation of LDA + U we report a successful study of this transition in low solute concentration magnesiowüstite, (Mg(1-x)Fe(x)(O), (x < 0.2) the second most abundant LM phase. We show that the HS-LS transition goes through an insulating (semiconducting) intermediate mixed spins (MS) state without discontinuous changes in properties, as seen experimentally. We show that the HS state crosses over smoothly to the LS state passing through an insulating MS state where properties change continuously, as seen experimentally.
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Affiliation(s)
- Taku Tsuchiya
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minnesota 55455, USA
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