1
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Truc B, Usai P, Pennacchio F, Berruto G, Claude R, Madan I, Sala V, LaGrange T, Vanacore GM, Benhabib S, Carbone F. Ultrafast generation of hidden phases via energy-tuned electronic photoexcitation in magnetite. Proc Natl Acad Sci U S A 2024; 121:e2316438121. [PMID: 38900799 PMCID: PMC11214049 DOI: 10.1073/pnas.2316438121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 04/26/2024] [Indexed: 06/22/2024] Open
Abstract
Phase transitions occurring in nonequilibrium conditions can evolve through high-energy intermediate states inaccessible via equilibrium adiabatic conditions. Because of the subtle nature of such hidden phases, their direct observation is extremely challenging and requires simultaneous visualization of matter at subpicoseconds and subpicometer scales. Here, we show that a magnetite crystal in the vicinity of its metal-to-insulator transition evolves through different hidden states when controlled via energy-tuned ultrashort laser pulses. By directly monitoring magnetite's crystal structure with ultrafast electron diffraction, we found that upon near-infrared (800 nm) excitation, the trimeron charge/orbital ordering pattern is destroyed in favor of a phase-separated state made of cubic-metallic and monoclinic-insulating regions. On the contrary, visible light (400 nm) activates a photodoping charge transfer process that further promotes the long-range order of the trimerons by stabilizing the charge density wave fluctuations, leading to the reinforcement of the monoclinic insulating phase. Our results demonstrate that magnetite's structure can evolve through completely different metastable hidden phases that can be reached long after the initial excitation has relaxed, breaking ground for a protocol to control emergent properties of matter.
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Affiliation(s)
- B. Truc
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - P. Usai
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - F. Pennacchio
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - G. Berruto
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - R. Claude
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - I. Madan
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - V. Sala
- Dipartimento di Fisica, Politecnico di Milano, Milano20133, Italy
| | - T. LaGrange
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - G. M. Vanacore
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
- Department of Materials Science, Laboratory of Ultrafast Microscopy for Nanoscale Dynamics, University of Milano-Bicocca, Milan20125, Italy
| | - S. Benhabib
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
- Centre national de la recherche scientifique, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay91405, France
| | - F. Carbone
- School of Basic Sciences, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
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2
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Wu SC, Lin CW, Chang PC, Yang TY, Tang SY, Wu DC, Liao CR, Wang YC, Lee L, Yu YJ, Chueh YL. Ecofriendly Synthesis of Waste-Tire-Derived Graphite Nanoflakes by a Low-Temperature Electrochemical Graphitization Process toward a Silicon-Based Anode with a High-Performance Lithium-Ion Battery. ACS APPLIED MATERIALS & INTERFACES 2023; 15:15279-15289. [PMID: 36921119 DOI: 10.1021/acsami.2c20393] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Here, the successful transformation of graphitic carbon with a high degree of graphitization and a nanoflake structure from pyrolytic tire carbon black was demonstrated. First, amorphous carbon black with a porous structure was obtained after pyrolysis and simple preacid treatments. Subsequently, the carbon black was converted into a highly graphitic structure at a relatively low temperature (850 °C) through a facile electrochemical route using molten salt, which is ecofriendly and has high potential for large-scale graphitization compared to conventional incineration techniques. Moreover, we further improved the crystallinity and uniformity of the product simultaneously by directly mixing the metal oxide catalyst Fe2O3 with a carbon precursor. The mechanism of this metal-catalyzed electrochemical graphitization has been discussed in detail. To confirm their potential in practical applications, the as-prepared graphitized nanoflakes were used as conductive additives for silicon anodes in lithium-ion batteries, which showed a performance comparable to those utilizing commercial Super-P additives, exhibiting an initial Coulombic efficiency of approximately 79.7% and a high capacity retention of approximately 45.8% after 100 cycles with a reversible capacity of 1220 mAh g-1 at a current rate of 400 mA g-1. Hence, successfully recovered waste-tire-derived carbon black utilizing a low-temperature Fe2O3-catalyzed electrochemical process opens a pathway in low-temperature graphitization toward a sustainable value-added application in the field of energy storage.
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Affiliation(s)
- Shu-Chi Wu
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Ching-Wei Lin
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Pai-Chun Chang
- Greenway Revolution Pte. Ltd., Bartley Ridge, Singapore 368063, Singapore
| | - Tzu-Yi Yang
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Shin-Yi Tang
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
| | - Ding-Chou Wu
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Cheng-Ru Liao
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Yi-Chung Wang
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Ling Lee
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
| | - Yi-Jen Yu
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
- Instrument Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yu-Lun Chueh
- Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
- College of Semiconductor Research, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yet-Sun University, Kaohsiung 80424, Taiwan
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3
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Balédent V, Nataf L, Rueff JP. Exceptionally robust magnetism and structure of SrFeO[Formula: see text] above 100 GPa. Sci Rep 2022; 12:16018. [PMID: 36163401 PMCID: PMC9512897 DOI: 10.1038/s41598-022-20192-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/09/2022] [Indexed: 11/25/2022] Open
Abstract
We report the exceptional structural and magnetic stability of SrFeO[Formula: see text] under pressure by X-Ray Magnetic Circular Dichroism (XMCD) and X-ray Diffraction (XRD) up to the Mbar range. The XMCD data confirm the onset of ferromagnetism above 30 GPa and its stability up to 102 GPa while XRD shows that SrFeO[Formula: see text] structure remains unchanged from 30 GPa up to 111 GPa without any sign of structural transition. Our results demonstrate the robustness of Fe properties under extreme conditions in the square planar environment.
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Affiliation(s)
- V. Balédent
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - L. Nataf
- Synchrotron SOLEIL, L’Orme des Merisiers, BP 48 St Aubin, 91192 Gif-sur-Yvette, France
| | - J.-P. Rueff
- Synchrotron SOLEIL, L’Orme des Merisiers, BP 48 St Aubin, 91192 Gif-sur-Yvette, France
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique–Matière et Rayonnement, LCPMR, 75005 Paris, France
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4
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Layek S, Greenberg E, Chariton S, Bykov M, Bykova E, Trots DM, Kurnosov AV, Chuvashova I, Ovsyannikov SV, Leonov I, Rozenberg GK. Verwey-Type Charge Ordering and Site-Selective Mott Transition in Fe 4O 5 under Pressure. J Am Chem Soc 2022; 144:10259-10269. [PMID: 35649281 PMCID: PMC9204770 DOI: 10.1021/jacs.2c00895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The metal–insulator transition
driven by electronic correlations
is one of the most fundamental concepts in condensed matter. In mixed-valence
compounds, this transition is often accompanied by charge ordering
(CO), resulting in the emergence of complex phases and unusual behaviors.
The famous example is the archetypal mixed-valence mineral magnetite,
Fe3O4, exhibiting a complex charge-ordering
below the Verwey transition, whose nature has been a subject of long-time
debates. In our study, using high-resolution X-ray diffraction supplemented
by resistance measurements and DFT+DMFT calculations, the electronic,
magnetic, and structural properties of recently synthesized mixed-valence
Fe4O5 are investigated under pressure to ∼100
GPa. Our calculations, consistent with experiment, reveal that at
ambient conditions Fe4O5 is a narrow-gap insulator
characterized by the original Verwey-type CO. Under pressure Fe4O5 undergoes a series of electronic and magnetic-state
transitions with an unusual compressional behavior above ∼50
GPa. A site-dependent collapse of local magnetic moments is followed
by the site-selective insulator-to-metal transition at ∼84
GPa, occurring at the octahedral Fe sites. This phase transition is
accompanied by a 2+ to 3+ valence change of the prismatic Fe ions
and collapse of CO. We provide a microscopic explanation of the complex
charge ordering in Fe4O5 which “unifies”
it with the behavior of two archetypal examples of charge- or bond-ordered
materials, magnetite and rare-earth nickelates (RNiO3).
We find that at low temperatures the Verwey-type CO competes with
the “trimeron”/“dimeron” charge ordered
states, allowing for pressure/temperature tuning of charge ordering.
Summing up the available data, we present the pressure–temperature
phase diagram of Fe4O5.
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Affiliation(s)
- Samar Layek
- School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv, Israel.,Department of Physics, School of Engineering, University of Petroleum and Energy Studies (UPES), Dehradun, Uttarakhand 248007, India
| | - Eran Greenberg
- Center for Advanced Radiation Sources, University of Chicago, 5640 South Ellis Avenue, 60637 Chicago, United States.,Applied Physics Division, Soreq NRC, Yavne, 81800, Israel
| | - Stella Chariton
- Center for Advanced Radiation Sources, University of Chicago, 5640 South Ellis Avenue, 60637 Chicago, United States
| | - Maxim Bykov
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Elena Bykova
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, District of Columbia 20015, United States.,Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Dmytro M Trots
- Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Alexander V Kurnosov
- Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Irina Chuvashova
- Harvard Physics, Jefferson Physical Lab, 17 Oxford Street, Cambridge, Massachusetts 02138, United States.,Department of Chemistry and Biochemistry, Florida International University, 11200 SW Eighth Street, CP 234, Miami, Florida 33199, United States
| | - Sergey V Ovsyannikov
- Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Ivan Leonov
- M. N. Miheev Institute of Metal Physics, Russian Academy of Sciences, 620108 Yekaterinburg, Russia.,Ural Federal University, 620002 Yekaterinburg, Russia.,Skolkovo Institute of Science and Technology, 143026 Moscow, Russia
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5
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Attfield JP. Magnetism and the Trimeron Bond. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2022; 34:2877-2885. [PMID: 35814039 PMCID: PMC9261838 DOI: 10.1021/acs.chemmater.2c00275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/14/2022] [Indexed: 05/06/2023]
Abstract
A review of progress in understanding the Verwey transition in magnetite (Fe3O4) over the past decade is presented. This electronic and structural transition at T V ≈ 125 K was reported in 1939 and has since been a contentious issue in magnetism. Long range Fe2+/Fe3+ charge ordering has been confirmed below the transition from crystal structure refinement, and Fe2+ orbital ordering and formation of trimerons through weak bonding of Fe2+ states to two Fe neighbors has been discovered. This model has accounted for many spectroscopic observations such as the 57Fe NMR frequencies. The trimeron lifetime has been measured, and trimeron soft modes have been observed. The origin of the first to second order crossover of Verwey transitions in doped magnetites has been revealed by a nanoparticle study. Electronic and structural fluctuations are found to persist to temperatures far above T V and local structural distortions track the bulk magnetization, disappearing at the 850 K Curie transition. New binary mixed-valent iron oxides discovered at high pressure are found to have electronic transitions and orbital molecule ground states similar to those of magnetite.
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6
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Dauphas N, Hu MY, Baker EM, Hu J, Tissot FLH, Alp EE, Roskosz M, Zhao J, Bi W, Liu J, Lin JF, Nie NX, Heard A. SciPhon: a data analysis software for nuclear resonant inelastic X-ray scattering with applications to Fe, Kr, Sn, Eu and Dy. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:1581-1599. [PMID: 30179200 PMCID: PMC6140397 DOI: 10.1107/s1600577518009487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/02/2018] [Indexed: 06/01/2023]
Abstract
The synchrotron radiation technique of nuclear resonant inelastic X-ray scattering (NRIXS), also known as nuclear resonance vibrational spectroscopy or nuclear inelastic scattering, provides a wealth of information on the vibrational properties of solids. It has found applications in studies of lattice dynamics and elasticity, superconductivity, heme biochemistry, seismology, isotope geochemistry and many other fields. It involves probing the vibrational modes of solids by using the nuclear resonance of Mössbauer isotopes such as 57Fe, 83Kr, 119Sn, 151Eu and 161Dy. After data reduction, it provides the partial phonon density of states of the Mössbauer isotope that is investigated, as well as many other derived quantities such as the mean force constant of the chemical bonds and the Debye velocity. The data reduction is, however, not straightforward and involves removal of the elastic peak, normalization and Fourier-Log transformation. Furthermore, some of the quantities derived are highly sensitive to details in the baseline correction. A software package and several novel procedures to streamline and hopefully improve the reduction of the NRIXS data generated at sector 3ID of the Advanced Photon Source have been developed. The graphical user interface software is named SciPhon and runs as a Mathematica package. It is easily portable to other platforms and can be easily adapted for reducing data generated at other beamlines. Several tests and comparisons are presented that demonstrate the usefulness of this software, whose results have already been used in several publications. Here, the SciPhon software is used to reduce Kr, Sn, Eu and Dy NRIXS data, and potential implications for interpreting natural isotopic variations in those systems are discussed.
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Affiliation(s)
- Nicolas Dauphas
- Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60615, USA
| | - Michael Y. Hu
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Erik M. Baker
- Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60615, USA
- Department of Earth and Planetary Sciences, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Justin Hu
- Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60615, USA
| | - Francois L. H. Tissot
- Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60615, USA
| | - E. Ercan Alp
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Mathieu Roskosz
- IMPMC-UMR CNRS 7590, Sorbonne Universités, UPMC, IRD, MNHN, Muséum National d’Histoire Naturelle, 61 Rue Buffon, 75005 Paris, France
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Wenli Bi
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Jin Liu
- Department of Geological Sciences, Stanford University, Stanford, CA, USA
| | - Jung-Fu Lin
- Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Nicole X. Nie
- Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60615, USA
| | - Andrew Heard
- Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60615, USA
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7
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Stability and anisotropy of (Fe xNi 1-x) 2O under high pressure and implications in Earth's and super-Earths' core. Sci Rep 2018; 8:236. [PMID: 29321631 PMCID: PMC5762755 DOI: 10.1038/s41598-017-18678-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/15/2017] [Indexed: 11/08/2022] Open
Abstract
Oxygen is thought to be an important light element in Earth's core but the amount of oxygen in Earth's core remains elusive. In addition, iron-rich iron oxides are of great interest and significance in the field of geoscience and condensed matter physics. Here, static calculations based on density functional theory demonstrate that I4/mmm-Fe2O is dynamically and mechanically stable and becomes energetically favorable with respect to the assemblage of hcp-Fe and [Formula: see text]-FeO above 270 GPa, which indicates that I4/mmm-Fe2O can be a strong candidate phase for stable iron-rich iron oxides at high pressure, perhaps even at high temperature. The elasticity and anisotropy of I4/mmm-(FexNi1-x)2O at high pressures are also determined. Based on these results, we have derived the upper limit of oxygen to be 4.3 wt% in Earth's lower outer core. On the other hand, I4/mmm-(FexNi1-x)2O with high AV S is likely to exist in a super-Earth's or an ocean planet's solid core causing the locally seismic heterogeneity. Our results not only give some clues to explore and synthesize novel iron-rich iron oxides but also shed light on the fundamental information of oxygen in the planetary core.
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8
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Fu S, Yang J, Lin JF. Abnormal Elasticity of Single-Crystal Magnesiosiderite across the Spin Transition in Earth's Lower Mantle. PHYSICAL REVIEW LETTERS 2017; 118:036402. [PMID: 28157335 DOI: 10.1103/physrevlett.118.036402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Indexed: 06/06/2023]
Abstract
Brillouin light scattering and impulsive stimulated light scattering have been used to determine the full elastic constants of magnesiosiderite [(Mg_{0.35}Fe_{0.65})CO_{3}] up to 70 GPa at room temperature in a diamond-anvil cell. Drastic softening in C_{11}, C_{33}, C_{12}, and C_{13} elastic moduli associated with the compressive stress component and stiffening in C_{44} and C_{14} moduli associated with the shear stress component are observed to occur within the spin transition between ∼42.4 and ∼46.5 GPa. Negative values of C_{12} and C_{13} are also observed within the spin transition region. The Born criteria constants for the crystal remain positive within the spin transition, indicating that the mixed-spin state remains mechanically stable. Significant auxeticity can be related to the electronic spin transition-induced elastic anomalies based on the analysis of Poisson's ratio. These elastic anomalies are explained using a thermoelastic model for the rhombohedral system. Finally, we conclude that mixed-spin state ferromagnesite, which is potentially a major deep-carbon carrier, is expected to exhibit abnormal elasticity, including a negative Poisson's ratio of -0.6 and drastically reduced V_{P} by 10%, in Earth's midlower mantle.
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Affiliation(s)
- Suyu Fu
- Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jing Yang
- Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jung-Fu Lin
- Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas 78712, USA
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9
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Legutko P, Jakubek T, Kaspera W, Stelmachowski P, Sojka Z, Kotarba A. Strong Enhancement of deSoot Activity of Transition Metal Oxides by Alkali Doping: Additive Effects of Potassium and Nitric Oxide. Top Catal 2016. [DOI: 10.1007/s11244-016-0727-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Zhang W, Zuo X, Zhang D, Wu C, Silva SRP. Cr(3+) substituted spinel ferrite nanoparticles with high coercivity. NANOTECHNOLOGY 2016; 27:245707. [PMID: 27159283 DOI: 10.1088/0957-4484/27/24/245707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The low coercivity of spinel ferrites is a major barrier that significantly limits their use in high density magnetic recording applications. By controlling the substituting content of Cr(3+), in this article we describe how magnetic CoCr x Fe2-x O4 (0 < x < 1.2) nanoparticles with coercivity of up to 6.4 kOe were successfully obtained by the hydrothermal process. The high coercivity is attributed to the synergetic effects of magnetocrystalline anisotropy and the nanoscale size effect. X-ray diffraction analysis confirmed the spinel structure of the nanoparticles with transmission electron microscopy (TEM) suggesting regular tetragonal morphology. The TEM indicated an edge length ranging from 15 nm to 150 nm, which increases monotonically with increasing Cr content. Raman analyses supported the proposed model on the formation mechanism of the nanoparticles, i.e. heterogeneous and homogeneous nucleation.
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Affiliation(s)
- Wei Zhang
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China
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