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Haraguchi Y, Nishio-Hamane D, Matsuo A, Kindo K, Katori HA. High-temperature magnetic anomaly via suppression of antisite disorder through synthesis route modification in a Kitaev candidate Cu 2IrO 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:405801. [PMID: 38941989 DOI: 10.1088/1361-648x/ad5d3a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 06/28/2024] [Indexed: 06/30/2024]
Abstract
By incorporating inert KCl into the Na2IrO3+ 2CuCl → Cu2IrO3+ 2NaCl topochemical reaction, we significantly reduced the synthesis temperature of Cu2IrO3from the 350 °C reported in previous studies to 170 °C. This adjustment decreased the Cu/Ir antisite disorder concentration in Cu2IrO3from ∼19% to ∼5%. Furthermore, magnetic susceptibility measurements of the present Cu2IrO3sample revealed a weak ferromagnetic-like anomaly with hysteresis at a magnetic transition temperature of ∼70 K. Our research indicates that the spin-disordered ground state reported in chemically disordered Cu2IrO3is an extrinsic phenomenon, rather than an intrinsic one, underscoring the pivotal role of synthetic chemistry in understanding the application of Kitaev model to realistic materials.
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Affiliation(s)
- Yuya Haraguchi
- Department of Applied Physics and Chemical Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Daisuke Nishio-Hamane
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Akira Matsuo
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Koichi Kindo
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Hiroko Aruga Katori
- Department of Applied Physics and Chemical Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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Krogel JT, Ichibha T, Saritas K, Yoon M, Reboredo FA. Predictions of delafossite-hosted honeycomb and kagome phases. Phys Chem Chem Phys 2024; 26:8327-8333. [PMID: 38391147 DOI: 10.1039/d3cp04039a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Delafossites, typically denoted by the formula ABO2, are a class of layered materials that exhibit a wide range of electronic and optical properties. Recently, the idea of modifying these delafossites into ordered kagome or honeycomb phases via strategic doping has emerged as a potential way to tailor these properties. In this study, we use high-throughput density functional theory calculations to explore many possible candidate kagome and honeycomb phases by considering dopants selected from the parent compounds of known ternary delafossite oxides from the inorganic crystal structure database. Our results indicate that while A-site in existing delafossites can host a limited range of elemental specifies, and display a low propensity for mixing or ordering, the oxide sub-units in the BO2 much more readily admit guest species. Our study identifies four candidate B-site kagome and fifteen candidate B-site honeycombs with a formation energy more than 50 meV f.u.-1 below other competing phases. The ability to predict and control the formation of these unique structures offers exciting opportunities in materials design, where innovative properties can be engineered through the selection of specific dopants. A number of these constitute novel correlated metals, which may be of interest for subsequent efforts in synthesis. These novel correlated metals may have significant implications for quantum computing, spintronics, and high-temperature superconductivity, thus inspiring future experimental synthesis and characterization of these proposed materials.
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Affiliation(s)
- Jaron T Krogel
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Tomohiro Ichibha
- School of Information Science, JAIST, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan
| | - Kayahan Saritas
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Mina Yoon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Fernando A Reboredo
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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3
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Bahrami F, Hu X, Du Y, Lebedev OI, Wang C, Luetkens H, Fabbris G, Graf MJ, Haskel D, Ran Y, Tafti F. First demonstration of tuning between the Kitaev and Ising limits in a honeycomb lattice. SCIENCE ADVANCES 2022; 8:eabl5671. [PMID: 35319975 PMCID: PMC8942356 DOI: 10.1126/sciadv.abl5671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 02/01/2022] [Indexed: 06/02/2023]
Abstract
Recent observations of novel spin-orbit coupled states have generated interest in 4d/5d transition metal systems. A prime example is the [Formula: see text] state in iridate materials and α-RuCl3 that drives Kitaev interactions. Here, by tuning the competition between spin-orbit interaction (λSOC) and trigonal crystal field (ΔT), we restructure the spin-orbital wave functions into a previously unobserved [Formula: see text] state that drives Ising interactions. This is done via a topochemical reaction that converts Li2RhO3 to Ag3LiRh2O6. Using perturbation theory, we present an explicit expression for the [Formula: see text] state in the limit ΔT ≫ λSOC realized in Ag3LiRh2O6, different from the conventional [Formula: see text] state in the limit λSOC ≫ ΔT realized in Li2RhO3. The change of ground state is followed by a marked change of magnetism from a 6 K spin-glass in Li2RhO3 to a 94 K antiferromagnet in Ag3LiRh2O6.
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Affiliation(s)
- Faranak Bahrami
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Xiaodong Hu
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Yonghua Du
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Oleg I. Lebedev
- Laboratoire CRISMAT, ENSICAEN-CNRS UMR6508, 14050 Caen, France
| | - Chennan Wang
- Laboratory for Muon Spin Spectroscopy (LMU), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Hubertus Luetkens
- Laboratory for Muon Spin Spectroscopy (LMU), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Gilberto Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Michael J. Graf
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Daniel Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Ying Ran
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
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4
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Bahrami F, Abramchuk M, Lebedev O, Tafti F. Metastable Kitaev Magnets. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030871. [PMID: 35164130 PMCID: PMC8840360 DOI: 10.3390/molecules27030871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/22/2022] [Accepted: 01/24/2022] [Indexed: 11/16/2022]
Abstract
Nearly two decades ago, Alexei Kitaev proposed a model for spin-1/2 particles with bond-directional interactions on a two-dimensional honeycomb lattice which had the potential to host a quantum spin-liquid ground state. This work initiated numerous investigations to design and synthesize materials that would physically realize the Kitaev Hamiltonian. The first generation of such materials, such as Na2IrO3, α-Li2IrO3, and α-RuCl3, revealed the presence of non-Kitaev interactions such as the Heisenberg and off-diagonal exchange. Both physical pressure and chemical doping were used to tune the relative strength of the Kitaev and competing interactions; however, little progress was made towards achieving a purely Kitaev system. Here, we review the recent breakthrough in modifying Kitaev magnets via topochemical methods that has led to the second generation of Kitaev materials. We show how structural modifications due to the topotactic exchange reactions can alter the magnetic interactions in favor of a quantum spin-liquid phase.
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Affiliation(s)
- Faranak Bahrami
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA; (F.B.); (M.A.)
| | - Mykola Abramchuk
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA; (F.B.); (M.A.)
| | - Oleg Lebedev
- Laboratoire CRISMAT, ENSICAEN-CNRS UMR6508, 14050 Caen, France;
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA; (F.B.); (M.A.)
- Correspondence:
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5
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Lawler KV, Smith D, Evans SR, Dos Santos AM, Molaison JJ, Bos JWG, Mutka H, Henry PF, Argyriou DN, Salamat A, Kimber SAJ. Decoupling Lattice and Magnetic Instabilities in Frustrated CuMnO 2. Inorg Chem 2021; 60:6004-6015. [PMID: 33788545 DOI: 10.1021/acs.inorgchem.1c00435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The AMnO2 delafossites (A = Na, Cu) are model frustrated antiferromagnets, with triangular layers of Mn3+ spins. At low temperatures (TN = 65 K), a C2/m → P1̅ transition is found in CuMnO2, which breaks frustration and establishes magnetic order. In contrast to this clean transition, A = Na only shows short-range distortions at TN. Here, we report a systematic crystallographic, spectroscopic, and theoretical investigation of CuMnO2. We show that, even in stoichiometric samples, nonzero anisotropic Cu displacements coexist with magnetic order. Using X-ray/neutron diffraction and Raman scattering, we show that high pressures act to decouple these degrees of freedom. This manifests as an isostuctural phase transition at ∼10 GPa, with a reversible collapse of the c-axis. This is shown to be the high-pressure analogue of the c-axis negative thermal expansion seen at ambient pressure. Density functional theory (DFT) simulations confirm that dynamical instabilities of the Cu+ cations and edge-shared MnO6 layers are intertwined at ambient pressure. However, high pressure selectively activates the former, before an eventual predicted reemergence of magnetism at the highest pressures. Our results show that the lattice dynamics and local structure of CuMnO2 are quantitatively different from nonmagnetic Cu delafossites and raise questions about the role of intrinsic inhomogeneity in frustrated antiferromagnets.
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Affiliation(s)
- Keith V Lawler
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, Las Vegas, Nevada 89154, United States
| | - Dean Smith
- Department of Physics and Astronomy and HiPSEC, University of Nevada Las Vegas, Las Vegas, Nevada 89154, United States
| | - Shaun R Evans
- European Synchrotron Radiation Facility - 71, avenue des Martyrs, CS 40220, 38043 Grenoble Cedex 9, France
| | - Antonio M Dos Santos
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jamie J Molaison
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jan-Willem G Bos
- Institute of Chemical Sciences, Centre for Advanced Energy Storage and Recovery, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Hannu Mutka
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble, France
| | - Paul F Henry
- ISIS Pulsed Neutron Muon Facility, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, United Kingdom
| | | | - Ashkan Salamat
- Department of Physics and Astronomy and HiPSEC, University of Nevada Las Vegas, Las Vegas, Nevada 89154, United States
| | - Simon A J Kimber
- ICB-Laboratoire Interdisciplinaire Carnot de Bourgogne, Bâtiment Sciences Mirande, Université Bourgogne-Franche Comté, Université de Bourgogne, 9 Avenue Alain Savary, B.P. 47870, 21078 Dijon Cedex, France
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Kuusela L, Veber A, Boetti NG, Petit L. Impact of ZnO Addition on Er 3+ Near-Infrared Emission, the Formation of Ag Nanoparticles, and the Crystallization of Sodium Fluorophosphate Glass. MATERIALS 2020; 13:ma13030527. [PMID: 31978992 PMCID: PMC7040811 DOI: 10.3390/ma13030527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/09/2020] [Accepted: 01/19/2020] [Indexed: 11/23/2022]
Abstract
The impact of the progressive addition of ZnO up to 5 mol% on the thermal, structural, and optical properties of Er3+-doped phosphate glasses within the system NaPO3-NaF-ZnO-Ag2O is discussed. The glass network was found to depolymerize upon the addition of ZnO. This promotes a slight increase in the intensity of the emission at 1.5 µm as well as enhances the silver ions clustering ability under the heat treating. The Ag-nanoparticles formed after moderate heat-treatment can further enhance the emission at 1.5 µm, whereas an excessive amount of the clusters leads to the opposite effect. The addition of ZnO helps to slightly increase the glass ability of the system. The crystallization behavior study revealed that surface crystallization is observed for all the glasses. It is found that even a small ZnO addition changes the crystalline phases formed after devitrification. Moreover, the addition of ZnO decreases the crystallization tendency of the glass.
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Affiliation(s)
- Luukas Kuusela
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (L.K.); (L.P.)
| | - Alexander Veber
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (L.K.); (L.P.)
- Correspondence:
| | - Nadia G. Boetti
- Fondazione LINKS—Leading Innovation & Knowledge for Society, Via P. C. Boggio 61, 10138 Torino, Italy;
| | - Laeticia Petit
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (L.K.); (L.P.)
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Bahrami F, Lafargue-Dit-Hauret W, Lebedev OI, Movshovich R, Yang HY, Broido D, Rocquefelte X, Tafti F. Thermodynamic Evidence of Proximity to a Kitaev Spin Liquid in Ag_{3}LiIr_{2}O_{6}. PHYSICAL REVIEW LETTERS 2019; 123:237203. [PMID: 31868481 DOI: 10.1103/physrevlett.123.237203] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/04/2019] [Indexed: 06/10/2023]
Abstract
Kitaev magnets are materials with bond-dependent Ising interactions between localized spins on a honeycomb lattice. Such interactions could lead to a quantum spin-liquid (QSL) ground state at zero temperature. Recent theoretical studies suggest two potential signatures of a QSL at finite temperatures, namely, a scaling behavior of thermodynamic quantities in the presence of quenched disorder, and a two-step release of the magnetic entropy. Here, we present both signatures in Ag_{3}LiIr_{2}O_{6} which is synthesized from α-Li_{2}IrO_{3} by replacing the interlayer Li atoms with Ag atoms. In addition, the dc susceptibility data confirm the absence of a long-range order, and the ac susceptibility data rule out a spin-glass transition. These observations suggest a closer proximity to the QSL in Ag_{3}LiIr_{2}O_{6} compared to its parent compound α-Li_{2}IrO_{3} that orders at 15 K. We discuss an enhanced spin-orbit coupling due to a mixing between silver d and oxygen p orbitals as a potential underlying mechanism.
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Affiliation(s)
- Faranak Bahrami
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - William Lafargue-Dit-Hauret
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, F-35000 Rennes, France
- Physique Théorique des Matériaux, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - Oleg I Lebedev
- Laboratoire CRISMAT, ENSICAEN-CNRS UMR6508, 14050 Caen, France
| | - Roman Movshovich
- MPA-CMMS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Hung-Yu Yang
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - David Broido
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - Xavier Rocquefelte
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, F-35000 Rennes, France
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
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