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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
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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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Shorikov AO, Streltsov SV. Importance of the many-body effects on the structural properties of the novel iron oxide Fe 2O. Phys Chem Chem Phys 2022; 24:12383-12388. [PMID: 35551355 DOI: 10.1039/d2cp01089e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The importance of many-body effects on the electronic and magnetic properties and stability of different structural phases was studied in novel iron oxide Fe2O. It was found that while Hubbard repulsion hardly affects the electronic spectrum of this material (m*/m ≈ 1.2), it strongly changes its phase diagram, shifting critical pressures of structural transitions to much lower values. Moreover, the P3̄m1 structure previously obtained in the density functional theory (DFT) becomes energetically unstable if many-body effects are taken into consideration. It is shown that these changes are due to magnetic moment fluctuations in the DFT+DMFT (method which combines density functional theory and dynamical mean-field theory) approach, which strongly modify the phase diagram of Fe2O.
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Affiliation(s)
- Alexey O Shorikov
- M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg, Russia. .,Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Mira St. 19, 620002 Yekaterinburg, Russia.,Skolkovo Institute of Science and Technology, 3 Nobel St., Moscow, 143026, Russia
| | - Sergey V Streltsov
- M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg, Russia. .,Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Mira St. 19, 620002 Yekaterinburg, Russia
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