1
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Manley ME, Stonaha PJ, Bruno NM, Karaman I, Arroyave R, Chi S, Abernathy DL, Stone MB, Chumlyakov YI, Lynn JW. Hybrid magnon-phonon localization enhances function near ferroic glassy states. SCIENCE ADVANCES 2024; 10:eadn2840. [PMID: 38875343 PMCID: PMC11177935 DOI: 10.1126/sciadv.adn2840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 05/09/2024] [Indexed: 06/16/2024]
Abstract
Ferroic materials on the verge of forming ferroic glasses exhibit heightened functionality that is often attributed to competing long- and short-range correlations. However, the physics underlying these enhancements is not well understood. The Ni45Co5Mn36.6In13.4 Heusler alloy is on the edge of forming both spin and strain glasses and exhibits magnetic field-induced shape memory and large magnetocaloric effects, making it a candidate for multicaloric cooling applications. We show using neutron scattering that localized magnon-phonon hybrid modes, which are inherently spread across reciprocal space, act as a bridge between phonons and magnons and result in substantial magnetic field-induced shifts in the phonons, triple the caloric response, and alter phase stability. We attribute these modes to the localization of phonons and magnons by antiphase boundaries coupled to magnetic domains. Because the interplay between short- and long-range correlations is common near ferroic glassy states, our work provides general insights on how glassiness enhances function.
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Affiliation(s)
- Michael E Manley
- Materials Sciences and Technology Division, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - Paul J Stonaha
- Materials Sciences and Technology Division, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - Nickolaus M Bruno
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA
- NASA Glenn Research Center, Cleveland, OH 44135, USA
| | - Ibrahim Karaman
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Raymundo Arroyave
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Songxue Chi
- Neutron Scattering Division, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - Douglas L Abernathy
- Neutron Scattering Division, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - Matthew B Stone
- Neutron Scattering Division, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - Yuri I Chumlyakov
- Siberian Physical Technical Institute, Tomsk State University, Tomsk, Russia
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
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2
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Riberolles SXM, Slade TJ, Dally RL, Sarte PM, Li B, Han T, Lane H, Stock C, Bhandari H, Ghimire NJ, Abernathy DL, Canfield PC, Lynn JW, Ueland BG, McQueeney RJ. Orbital character of the spin-reorientation transition in TbMn 6Sn 6. Nat Commun 2023; 14:2658. [PMID: 37160929 PMCID: PMC10169834 DOI: 10.1038/s41467-023-38174-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 04/19/2023] [Indexed: 05/11/2023] Open
Abstract
Ferromagnetic (FM) order in a two-dimensional kagome layer is predicted to generate a topological Chern insulator without an applied magnetic field. The Chern gap is largest when spin moments point perpendicular to the kagome layer, enabling the capability to switch topological transport properties, such as the quantum anomalous Hall effect, by controlling the spin orientation. In TbMn6Sn6, the uniaxial magnetic anisotropy of the Tb3+ ion is effective at generating the Chern state within the FM Mn kagome layers while a spin-reorientation (SR) transition to easy-plane order above TSR = 310 K provides a mechanism for switching. Here, we use inelastic neutron scattering to provide key insights into the fundamental nature of the SR transition. The observation of two Tb excitations, which are split by the magnetic anisotropy energy, indicates an effective two-state orbital character for the Tb ion, with a uniaxial ground state and an isotropic excited state. The simultaneous observation of both modes below TSR confirms that orbital fluctuations are slow on magnetic and electronic time scales < ps and act as a spatially-random orbital alloy. A thermally-driven critical concentration of isotropic Tb ions triggers the SR transition.
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Affiliation(s)
| | - Tyler J Slade
- Ames National Laboratory, Ames, Iowa, 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - R L Dally
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - P M Sarte
- Materials Department and California Nanosystems Institute, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Bing Li
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - Tianxiong Han
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - H Lane
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3JZ, United Kingdom
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - C Stock
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3JZ, United Kingdom
| | - H Bhandari
- Department of Physics and Astronomy, George Mason University, Fairfax, VA, 22030, USA
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA, 22030, USA
| | - N J Ghimire
- Department of Physics and Astronomy, George Mason University, Fairfax, VA, 22030, USA
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA, 22030, USA
| | - D L Abernathy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - P C Canfield
- Ames National Laboratory, Ames, Iowa, 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - J W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - B G Ueland
- Ames National Laboratory, Ames, Iowa, 50011, USA
| | - R J McQueeney
- Ames National Laboratory, Ames, Iowa, 50011, USA.
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA.
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3
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Honecker D, Bersweiler M, Erokhin S, Berkov D, Chesnel K, Venero DA, Qdemat A, Disch S, Jochum JK, Michels A, Bender P. Using small-angle scattering to guide functional magnetic nanoparticle design. NANOSCALE ADVANCES 2022; 4:1026-1059. [PMID: 36131777 PMCID: PMC9417585 DOI: 10.1039/d1na00482d] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 01/15/2022] [Indexed: 05/14/2023]
Abstract
Magnetic nanoparticles offer unique potential for various technological, biomedical, or environmental applications thanks to the size-, shape- and material-dependent tunability of their magnetic properties. To optimize particles for a specific application, it is crucial to interrelate their performance with their structural and magnetic properties. This review presents the advantages of small-angle X-ray and neutron scattering techniques for achieving a detailed multiscale characterization of magnetic nanoparticles and their ensembles in a mesoscopic size range from 1 to a few hundred nanometers with nanometer resolution. Both X-rays and neutrons allow the ensemble-averaged determination of structural properties, such as particle morphology or particle arrangement in multilayers and 3D assemblies. Additionally, the magnetic scattering contributions enable retrieving the internal magnetization profile of the nanoparticles as well as the inter-particle moment correlations caused by interactions within dense assemblies. Most measurements are used to determine the time-averaged ensemble properties, in addition advanced small-angle scattering techniques exist that allow accessing particle and spin dynamics on various timescales. In this review, we focus on conventional small-angle X-ray and neutron scattering (SAXS and SANS), X-ray and neutron reflectometry, gracing-incidence SAXS and SANS, X-ray resonant magnetic scattering, and neutron spin-echo spectroscopy techniques. For each technique, we provide a general overview, present the latest scientific results, and discuss its strengths as well as sample requirements. Finally, we give our perspectives on how future small-angle scattering experiments, especially in combination with micromagnetic simulations, could help to optimize the performance of magnetic nanoparticles for specific applications.
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Affiliation(s)
- Dirk Honecker
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory Didcot OX11 0QX UK
| | - Mathias Bersweiler
- Department of Physics and Materials Science, University of Luxembourg 162A Avenue de La Faïencerie L-1511 Luxembourg Grand Duchy of Luxembourg
| | - Sergey Erokhin
- General Numerics Research Lab Moritz-von-Rohr-Straße 1A D-07745 Jena Germany
| | - Dmitry Berkov
- General Numerics Research Lab Moritz-von-Rohr-Straße 1A D-07745 Jena Germany
| | - Karine Chesnel
- Brigham Young University, Department of Physics and Astronomy Provo Utah 84602 USA
| | - Diego Alba Venero
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory Didcot OX11 0QX UK
| | - Asma Qdemat
- Universität zu Köln, Department für Chemie Luxemburger Straße 116 D-50939 Köln Germany
| | - Sabrina Disch
- Universität zu Köln, Department für Chemie Luxemburger Straße 116 D-50939 Köln Germany
| | - Johanna K Jochum
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München Lichtenbergstraße 1 85748 Garching Germany
| | - Andreas Michels
- Department of Physics and Materials Science, University of Luxembourg 162A Avenue de La Faïencerie L-1511 Luxembourg Grand Duchy of Luxembourg
| | - Philipp Bender
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München Lichtenbergstraße 1 85748 Garching Germany
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4
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Kim MG, Ratcliff W, Pajerowski DM, Kim JW, Yan JQ, Lynn JW, Goldman AI, Kreyssig A. Magnetic ordering and structural distortion in a PrFeAsO single crystal studied by neutron and x-ray scattering. PHYSICAL REVIEW. B 2021; 103:10.1103/physrevb.103.174405. [PMID: 37588030 PMCID: PMC10428661 DOI: 10.1103/physrevb.103.174405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
We report the magnetic ordering and structural distortion in PrFeAsO crystals, the basis compound for one of the oxypnictide superconductors, using high-resolution x-ray diffraction, neutron diffraction, and x-ray resonant magnetic scattering (XRMS). We find the structural tetragonal-to-orthorhombic phase transition at T S = 147 K , the AFM phase transition of the Fe moments at T Fe = 72 K , and the Pr AFM phase transition at T Pr = 21 K . Combined high-resolution neutron diffraction and XRMS show unambiguously that the Pr moments point parallel to the longer orthorhombic a axis and order antiferromagnetically along the a axis but ferromagnetically along the b and c directions in the stripelike AFM order. The temperature-dependent magnetic order parameter of the Pr moments shows no evidence for a reorientation of moments.
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Affiliation(s)
- M. G. Kim
- Department of Physics, University of Wisconsin at Milwaukee, Milwaukee, Wisconsin 53201, USA
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
- Ames Laboratory, US DOE, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - W. Ratcliff
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - D. M. Pajerowski
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J.-W. Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J.-Q. Yan
- Ames Laboratory, US DOE, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - J. W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - A. I. Goldman
- Ames Laboratory, US DOE, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - A. Kreyssig
- Ames Laboratory, US DOE, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
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5
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Li WH, Lee CH, Ling TY, Ma MH, Wei PC, He JH, Wu CM, Peng JC, Xu G, Zhao Y, Lynn JW. Enhanced lattice perfection by low temperature thermal annealing in photoelectric (CH 3NH 3)PbBr 3. PHYSICAL REVIEW MATERIALS 2021; 5:10.1103/PhysRevMaterials.5.025401. [PMID: 38487078 PMCID: PMC10938366 DOI: 10.1103/physrevmaterials.5.025401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
The coupling between the organic CH3NH3+ cations and inorganic perovskite PbBr3- framework in a large single crystal of (CH3NH3)PbBr3 weighting 13 g was studied using neutron diffraction and inelastic neutron scattering. Two lattice incommensurate (ICM) phases were found, one at higher temperatures, marked ICMHT, which appeared between 147 and 135 K. The second one, marked ICMLT, developed below 143 K and remained at 75 K. The transition from the ICMLT to ICMHT phase upon warming gave rise to extremely large lattice shrinking, followed by extremely large lattice expansion of the tetragonal basal plane of the PbBr3 lattice. There was a progressive decrease in the width of the Bragg peaks from the PbBr3 lattice upon warming, which can be described using a critical exponent for each type of Bragg peak to show complete ordering of the atoms into a (CH3NH3)PbBr3 lattice at 194 K. (CH3NH3)PbBr3 exhibits six definitive acoustic-like phonon branches at 75 K. The six branches renormalizes into two at 200 K, with the frequencies of both the transverse and longitudinal modes greatly enhanced. The asymmetric structure of the CH3NH3 ions helps to understand the observed behaviors.
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Affiliation(s)
- Wen-Hsien Li
- Department of Physics, National Central University, Jhongli 32001, Taiwan
| | - Chi-Hung Lee
- Department of Physics, National Central University, Jhongli 32001, Taiwan
| | - Tsu-Yin Ling
- Department of Physics, National Central University, Jhongli 32001, Taiwan
| | - Ma-Hsuan Ma
- Department of Physics, National Central University, Jhongli 32001, Taiwan
| | - Pai-Chun Wei
- Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science & Technology, Saudi Arabia
| | - Jr-Hau He
- Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science & Technology, Saudi Arabia
| | - Chun-Min Wu
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Jen-Chih Peng
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Guangyong Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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6
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Dally RL, Phelan D, Bishop N, Ghimire NJ, Lynn JW. Isotropic Nature of the Metallic Kagome Ferromagnet Fe 3Sn 2 at High Temperatures. CRYSTALS 2021; 11:10.3390/cryst11030307. [PMID: 38487672 PMCID: PMC10938373 DOI: 10.3390/cryst11030307] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anisotropy and competing exchange interactions have emerged as two central ingredients needed for centrosymmetric materials to exhibit topological spin textures. Fe3Sn2 is thought to have these ingredients as well, as it has recently been discovered to host room temperature skyrmionic bubbles with an accompanying topological Hall effect. We present small-angle inelastic neutron scattering measurements that unambiguously show that Fe3Sn2 is an isotropic ferromagnet below T C ≈ 660 K to at least 480 K - the lower temperature threshold of our experimental configuration. Fe3Sn2 is known to have competing magnetic exchange interactions, correlated electron behavior, weak magnetocrystalline anisotropy, and lattice anisotropy; all of these features are thought to play a role in stabilizing skyrmions in centrosymmetric systems. Our results reveal that at elevated temperatures, there is an absence of magnetocrystalline anisotropy and that the system behaves as a typical exchange ferromagnet with a spin stiffness D T = 0 K = 271 ± 9 meV Å 2 .
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Affiliation(s)
- Rebecca L. Dally
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102
| | - Daniel Phelan
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Nicholas Bishop
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030
| | - Nirmal J. Ghimire
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA 22030
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102
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7
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Ghimire NJ, Dally RL, Poudel L, Jones DC, Michel D, Magar NT, Bleuel M, McGuire MA, Jiang JS, Mitchell JF, Lynn JW, Mazin II. Competing magnetic phases and fluctuation-driven scalar spin chirality in the kagome metal YMn 6Sn 6. SCIENCE ADVANCES 2020; 6:eabe2680. [PMID: 33355145 PMCID: PMC11206209 DOI: 10.1126/sciadv.abe2680] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/02/2020] [Indexed: 05/25/2023]
Abstract
Identification, understanding, and manipulation of novel magnetic textures are essential for the discovery of new quantum materials for future spin-based electronic devices. In particular, materials that manifest a large response to external stimuli such as a magnetic field are subject to intense investigation. Here, we study the kagome-net magnet YMn6Sn6 by magnetometry, transport, and neutron diffraction measurements combined with first-principles calculations. We identify a number of nontrivial magnetic phases, explain their microscopic nature, and demonstrate that one of them hosts a large topological Hall effect (THE). We propose a previously unidentified fluctuation-driven mechanism, which leads to the THE at elevated temperatures. This interesting physics comes from parametrically frustrated interplanar exchange interactions that trigger strong magnetic fluctuations. Our results pave a path to chiral spin textures, promising for novel spintronics.
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Affiliation(s)
- Nirmal J Ghimire
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA.
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA 22030, USA
| | - Rebecca L Dally
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - L Poudel
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - D C Jones
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA 22030, USA
| | - D Michel
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA 22030, USA
| | - N Thapa Magar
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA
| | - M Bleuel
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Michael A McGuire
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - J S Jiang
- Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - I I Mazin
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA
- Quantum Science and Engineering Center, George Mason University, Fairfax, VA 22030, USA
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8
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Liu P, Klemm ML, Tian L, Lu X, Song Y, Tam DW, Schmalzl K, Park JT, Li Y, Tan G, Su Y, Bourdarot F, Zhao Y, Lynn JW, Birgeneau RJ, Dai P. In-plane uniaxial pressure-induced out-of-plane antiferromagnetic moment and critical fluctuations in BaFe 2As 2. Nat Commun 2020; 11:5728. [PMID: 33184278 PMCID: PMC7665052 DOI: 10.1038/s41467-020-19421-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 10/12/2020] [Indexed: 11/29/2022] Open
Abstract
A small in-plane external uniaxial pressure has been widely used as an effective method to acquire single domain iron pnictide BaFe2As2, which exhibits twin-domains without uniaxial strain below the tetragonal-to-orthorhombic structural (nematic) transition temperature Ts. Although it is generally assumed that such a pressure will not affect the intrinsic electronic/magnetic properties of the system, it is known to enhance the antiferromagnetic (AF) ordering temperature TN ( < Ts) and create in-plane resistivity anisotropy above Ts. Here we use neutron polarization analysis to show that such a strain on BaFe2As2 also induces a static or quasi-static out-of-plane (c-axis) AF order and its associated critical spin fluctuations near TN/Ts. Therefore, uniaxial pressure necessary to detwin single crystals of BaFe2As2 actually rotates the easy axis of the collinear AF order near TN/Ts, and such effects due to spin-orbit coupling must be taken into account to unveil the intrinsic electronic/magnetic properties of the system.
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Affiliation(s)
- Panpan Liu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, 100875, Beijing, China
| | - Mason L Klemm
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
| | - Long Tian
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, 100875, Beijing, China
| | - Xingye Lu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, 100875, Beijing, China.
| | - Yu Song
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - David W Tam
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
| | - Karin Schmalzl
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at ILL, 71 avenue des Martyrs, 38000, Grenoble, France
| | - J T Park
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, 85748, Garching, Germany
| | - Yu Li
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
| | - Guotai Tan
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, 100875, Beijing, China
| | - Yixi Su
- Jülich Centre for Neutron Science JCNS at MLZ, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747, Garching, Germany
| | | | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Jeffery W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Robert J Birgeneau
- Department of Physics, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA.
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9
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Nguyen T, Han F, Andrejevic N, Pablo-Pedro R, Apte A, Tsurimaki Y, Ding Z, Zhang K, Alatas A, Alp EE, Chi S, Fernandez-Baca J, Matsuda M, Tennant DA, Zhao Y, Xu Z, Lynn JW, Huang S, Li M. Topological Singularity Induced Chiral Kohn Anomaly in a Weyl Semimetal. PHYSICAL REVIEW LETTERS 2020; 124:236401. [PMID: 32603171 PMCID: PMC7935413 DOI: 10.1103/physrevlett.124.236401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
The electron-phonon interaction (EPI) is instrumental in a wide variety of phenomena in solid-state physics, such as electrical resistivity in metals, carrier mobility, optical transition, and polaron effects in semiconductors, lifetime of hot carriers, transition temperature in BCS superconductors, and even spin relaxation in diamond nitrogen-vacancy centers for quantum information processing. However, due to the weak EPI strength, most phenomena have focused on electronic properties rather than on phonon properties. One prominent exception is the Kohn anomaly, where phonon softening can emerge when the phonon wave vector nests the Fermi surface of metals. Here we report a new class of Kohn anomaly in a topological Weyl semimetal (WSM), predicted by field-theoretical calculations, and experimentally observed through inelastic x-ray and neutron scattering on WSM tantalum phosphide. Compared to the conventional Kohn anomaly, the Fermi surface in a WSM exhibits multiple topological singularities of Weyl nodes, leading to a distinct nesting condition with chiral selection, a power-law divergence, and non-negligible dynamical effects. Our work brings the concept of the Kohn anomaly into WSMs and sheds light on elucidating the EPI mechanism in emergent topological materials.
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Affiliation(s)
- Thanh Nguyen
- Department of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Fei Han
- Department of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Nina Andrejevic
- Department of Materials Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Ricardo Pablo-Pedro
- Department of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Anuj Apte
- Department of Physics, MIT, Cambridge, Massachusetts 02139, USA
| | - Yoichiro Tsurimaki
- Department of Mechanical Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Zhiwei Ding
- Department of Materials Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Kunyan Zhang
- Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Ahmet Alatas
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ercan E. Alp
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Songxue Chi
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Jaime Fernandez-Baca
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Masaaki Matsuda
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - David Alan Tennant
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Zhijun Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Shengxi Huang
- Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Mingda Li
- Department of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA
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10
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Yu J, Wang M, Frandsen BA, Sun H, Yin J, Liu Z, Wu S, Yi M, Xu Z, Acharya A, Huang Q, Bourret-Courchesne E, Lynn JW, Birgeneau RJ. Structural, magnetic, and electronic evolution of the spin-ladder system BaFe 2S 3-x Se x with isoelectronic substitution. PHYSICAL REVIEW. B 2020; 101:10.1103/PhysRevB.101.235134. [PMID: 34136736 PMCID: PMC8204408 DOI: 10.1103/physrevb.101.235134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report experimental studies of a series of BaFe2S3-x Se x (0 ⩽ x ⩽ 3) single crystals and powder specimens using x-ray diffraction, neutron-diffraction, muon-spin-relaxation, and electrical transport measurements. A structural transformation from Cmcm (BaFe2S3) to Pnma (BaFe2Se3) was identified around x = 0.7 - 1. Neutron-diffraction measurements on the samples with x = 0.2, 0.4, and 0.7 reveal that the Néel temperature of the stripe antiferromagnetic order is gradually suppressed from ~120 to 85 K, while the magnitude of the ordered Fe2+ moments shows very little variation. Similarly, the block antiferromagnetic order in BaFe2Se3 remains robust for 1.5 ⩽ x ⩽ 3 with negligible variation in the ordered moment and a slight decrease of the Néel temperature from 250 K (x = 3) to 225 K (x = 1.5). The sample with x = 1 near the Cmcm and Pnma border shows coexisting, two-dimensional, short-range stripe- and block-type antiferromagnetic correlations. The system remains insulating for all x, but the thermal activation gap shows an abrupt increase when traversing the boundary from the Cmcm stripe phase to the Pnma block phase. The results demonstrate that the crystal structure, magnetic order, and electronic properties are strongly coupled in the BaFe2S3-x Se x system.
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Affiliation(s)
- Jia Yu
- School of Physics, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Meng Wang
- School of Physics, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Benjamin A. Frandsen
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA
| | - Hualei Sun
- School of Physics, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Junjie Yin
- School of Physics, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Zengjia Liu
- School of Physics, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Shan Wu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Ming Yi
- Department of Physics, University of California, Berkeley, California 94720, USA
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - Zhijun Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Arani Acharya
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Qingzhen Huang
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Edith Bourret-Courchesne
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Robert J. Birgeneau
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
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11
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Piva MM, Tartaglia R, Freitas GS, Souza JC, Christovam DS, Thomas SM, Leão JB, Ratcliff W, Lynn JW, Lane C, Zhu JX, Thompson JD, Rosa PFS, Adriano C, Granado E, Pagliuso PG. Electronic and magnetic properties of stoichiometric CeAuBi 2. PHYSICAL REVIEW. B 2020; 101:10.1103/PhysRevB.101.214431. [PMID: 34141976 PMCID: PMC8207490 DOI: 10.1103/physrevb.101.214431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report the electronic and magnetic properties of stoichiometric CeAuBi2 single crystals. At ambient pressure, CeAuBi2 orders antiferromagnetically below a Néel temperature (TN ) of 19 K. Neutron diffraction experiments revealed an antiferromagnetic propagation vector τ ^ = [ 0 , 0 , 1 ∕ 2 ] , which doubles the paramagnetic unit cell along the c axis. At low temperatures several metamagnetic transitions are induced by the application of fields parallel to the c axis, suggesting that the magnetic structure of CeAuBi2 changes as a function of field. At low temperatures, a linear positive magnetoresistance may indicate the presence of band crossings near the Fermi level. Finally, the application of external pressure favors the antiferromagnetic state, indicating that the 4f electrons become more localized.
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Affiliation(s)
- M. M. Piva
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, D-01187 Dresden, Germany
| | - R. Tartaglia
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
| | - G. S. Freitas
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
| | - J. C. Souza
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
| | - D. S. Christovam
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
| | - S. M. Thomas
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J. B. Leão
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - W. Ratcliff
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J. W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - C. Lane
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J.-X. Zhu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J. D. Thompson
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - P. F. S. Rosa
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C. Adriano
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
| | - E. Granado
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
| | - P. G. Pagliuso
- Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo, Brazil
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12
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Porter Z, Need RF, Ahadi K, Zhao Y, Xu Z, Kirby BJ, Lynn JW, Stemmer S, Wilson SD. Correlating magnetic structure and magnetotransport in semimetal thin films of Eu 1-x Sm x TiO 3. PHYSICAL REVIEW MATERIALS 2020; 4:10.1103/PhysRevMaterials.4.054411. [PMID: 34142004 PMCID: PMC8207484 DOI: 10.1103/physrevmaterials.4.054411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report on the evolution of the average and depth-dependent magnetic order in thin-film samples of biaxially stressed and electron-doped EuTiO3 for samples across a doping range < 0.1 to 7.8 × 1020 cm-3. Under an applied in-plane magnetic field, the G-type antiferromagnetic ground state undergoes a continuous spin-flop phase transition into in-plane, field-polarized ferromagnetism. The critical field for ferromagnetism slightly decreases with an increasing number of free carriers, yet the field evolution of the spin-flop transition is qualitatively similar across the doping range. Unexpectedly, we observe interfacial ferromagnetism with saturated Eu2+ moments at the substrate interface at low fields preceding ferromagnetic saturation throughout the bulk of the degenerate semiconductor film. We discuss the implications of these findings for the unusual magnetotransport properties of this compound.
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Affiliation(s)
- Zach Porter
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - Ryan F. Need
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Kaveh Ahadi
- Materials Department, University of California, Santa Barbara, California 93106, USA
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Zhijun Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Brian J. Kirby
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - Stephen D. Wilson
- Materials Department, University of California, Santa Barbara, California 93106, USA
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13
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Lussier JA, Richtik BN, Mauws C, Lynn JW, Wiebe CR. Absence of magnetic ordering in the spin liquid candidate Ca 3Cu 2GeV 2O 12. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:134001. [PMID: 31775126 PMCID: PMC11134417 DOI: 10.1088/1361-648x/ab5c7b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Typically, quantum spin liquid candidates can be found in materials with a combination of geometrical frustration along with low spin. Due to its spin of S = 1/2 the copper (II) ion is often present in the discussion on spin liquid candidates. The solid state compound Ca3Cu2GeV2O12 is a material that crystallizes in the garnet structure (s.g. #230, Ia-3d), where 3D frustration is known to occur. Heat capacity has shown a lack of magnetic ordering down to 0.35 K, confirmed with low temperature neutron diffraction to 0.07 K. This system displays a Weiss temperature of -0.93(1) K indicating net antiferromagnetic interactions and significant J 1-J 2 competition causing frustration. Using both neutron and x-ray diffraction along with heat capacity and magnetometry, the work presented here shows Ca3Cu2GeV2O12 has potential as a new spin liquid candidate.
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Affiliation(s)
- Joey A Lussier
- Department of Chemistry, University of Winnipeg, Winnipeg, Canada
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14
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Wang M, Yi M, Frandsen BA, Yin J, Sun H, Xu Z, Cao H, Bourret-Courchesne E, Lynn JW, Birgeneau RJ. Observation of a C-type short-range antiferromagnetic order in layer spacing expanded FeS. PHYSICAL REVIEW MATERIALS 2020; 4:10.1103/physrevmaterials.4.034802. [PMID: 33659774 PMCID: PMC7923892 DOI: 10.1103/physrevmaterials.4.034802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report neutron diffraction studies of FeS single crystals obtained from Rb x Fe2-y S2 single crystals via a hydrothermal method. While no 5 × 5 iron vacancy order or block antiferromagnetic order typical of Rb x Fe2-y S2 is found in our samples, we observe C-type short-range antiferromagnetic order with moments pointed along the c axis hosted by a different phase of FeS with an expanded interlayer spacing. The Néel temperature for this magnetic order is determined to be 170 ± 4 K. Our finding of a variant FeS structure hosting this C-type antiferromagnetic order demonstrates that the known FeS phase synthesized in this method is in the vicinity of a magnetically ordered ground state, providing insights into understanding a variety of phenomena observed in FeS and the related FeSe1-x S x iron chalcogenide system.
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Affiliation(s)
- Meng Wang
- School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Ming Yi
- Department of Physics, University of California, Berkeley, California 94720, USA
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - Benjamin A. Frandsen
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Junjie Yin
- School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Hualei Sun
- School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Zhijun Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Huibo Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Edith Bourret-Courchesne
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Robert J. Birgeneau
- Department of Physics, University of California, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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15
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Gundogdu S, Clancy JP, Xu G, Zhao Y, Dube PA, Karalar TC, Cho BK, Lynn JW, Ramazanoglu M. Magnetic order and competition with superconductivity in (Ho-Er)Ni 2B 2C. MATERIALS RESEARCH EXPRESS 2020; 7:10.1088/2053-1591/abc998. [PMID: 37719937 PMCID: PMC10502616 DOI: 10.1088/2053-1591/abc998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
The rare earth magnetic order in pure and doped H o ( 1 - x ) E r x N i 2 B 2 C (x = 0, 0.25, 0.50, 0.75, 1) single crystal samples was investigated using magnetization and neutron diffraction measurements. Superconducting quaternary borocarbides, R N i 2 B 2 C where R = Ho, Er , are magnetic intermetallic superconductors with the transition temperatures~10 K in which long range magnetic order develops in the same temperature range and competes with superconductivity. Depending on the rare earth composition the coupling between superconductivity and magnetism creates several phases, ranging from a near reentrant superconductor with a mixture of commensurate and incommensurate antiferromagnetism to an incommensurate antiferromagnetic spin modulation with a weak ferromagnetic component. All of these phases coexist with superconductivity. RKKY magnetic interactions are used to describe the magnetic orders in the pure compounds. However, the doping of Er on Ho sites which have two strong magnetic moments with two different easy directions creates new and complicated magnetic modulations with possible local disorder effects. One fascinating effect is the development of an induced magnetic state resembling the pure and doped R2CuO4 cuprate with R = Nd and Pr.
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Affiliation(s)
- Suleyman Gundogdu
- Physics Engineering Department, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
| | - J Patrick Clancy
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 Canada
| | - Guangyong Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Paul A Dube
- Brockhouse Institute for Materials Research, Hamilton, ON L8S 4M1, Canada
| | - Tufan C Karalar
- Electronics and Communication Engineering Department, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
| | - Beong Ki Cho
- Gwangju Institute of Science and Technology, GIST, Republic of Korea
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - M Ramazanoglu
- Physics Engineering Department, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
- Brockhouse Institute for Materials Research, Hamilton, ON L8S 4M1, Canada
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16
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Pandey A, Miao P, Klemm M, He H, Wang H, Qian X, Lynn JW, Aronson MC. Correlations and incipient antiferromagnetic order within the linear Mn chains of metallic Ti 4MnBi 2. PHYSICAL REVIEW. B 2020; 102:10.1103/PhysRevB.102.014406. [PMID: 34136737 PMCID: PMC8204450 DOI: 10.1103/physrevb.102.014406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report measurements on Ti4MnBi2, where a crystal structure involving linear chains of Mn ions suggests one-dimensional magnetic character. The electrical resistivity is metallic, consistent with the results of electronic-structure calculations that find a robust Fermi surface albeit with moderate electronic correlations. A Curie-Weiss fit to the magnetic susceptibility suggests that the Mn moments are in the low-spin S = 1/2 configuration. Neutron diffraction measurements detect weak antiferromagnetic order within the Mn chains, with further evidence for the small staggered moment coming from the entropy associated with the ordering peak in the specific heat as well as from the results of spin-polarized electronic-structure calculations. The antiferromagnetic moments are apparently associated with thed x 2 - y 2 and d xy orbitals of Mn while the remaining Mn orbitals are delocalized and nonmagnetic. Strong quantum fluctuations, possibly related to an electronic instability that forms the Mn moment or to the one-dimensional character of Ti4MnBi2, nearly overcome magnetic order.
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Affiliation(s)
- Abhishek Pandey
- School of Physics, University of the Witwatersrand, Johannesburg, Gauteng 2050, South Africa
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - Ping Miao
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - M. Klemm
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - H. He
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - H. Wang
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - X. Qian
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - J. W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - M. C. Aronson
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, USA
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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17
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Smaha RW, He W, Jiang JM, Wen J, Jiang YF, Sheckelton JP, Titus CJ, Wang SG, Chen YS, Teat SJ, Aczel AA, Zhao Y, Xu G, Lynn JW, Jiang HC, Lee YS. Materializing rival ground states in the barlowite family of kagome magnets: quantum spin liquid, spin ordered, and valence bond crystal states. NPJ QUANTUM MATERIALS 2020; 5:https://doi.org/10.1038/s41535-020-0222-8. [PMID: 33072886 PMCID: PMC7558222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The spin- 1 2 kagome antiferromagnet is considered an ideal host for a quantum spin liquid (QSL) ground state. We find that when the bonds of the kagome lattice are modulated with a periodic pattern, new quantum ground states emerge. Newly synthesized crystalline barlowite (Cu4(OH)6FBr) and Zn-substituted barlowite demonstrate the delicate interplay between singlet states and spin order on the spin- 1 2 kagome lattice. Comprehensive structural measurements demonstrate that our new variant of barlowite maintains hexagonal symmetry at low temperatures with an arrangement of distorted and undistorted kagome triangles, for which numerical simulations predict a pinwheel valence bond crystal (VBC) state instead of a QSL. The presence of interlayer spins eventually leads to an interesting pinwheel q = 0 magnetic order. Partially Zn-substituted barlowite (Cu3.44Zn0.56(OH)6FBr) has an ideal kagome lattice and shows QSL behavior, indicating a surprising robustness of the QSL against interlayer impurities. The magnetic susceptibility is similar to that of herbertsmithite, even though the Cu2+ impurities are above the percolation threshold for the interlayer lattice and they couple more strongly to the nearest kagome moment. This system is a unique playground displaying QSL, VBC, and spin order, furthering our understanding of these highly competitive quantum states.
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Affiliation(s)
- Rebecca W Smaha
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
- These authors contributed equally: Rebecca W. Smaha, Wei He
| | - Wei He
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- These authors contributed equally: Rebecca W. Smaha, Wei He
| | - Jack Mingde Jiang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Jiajia Wen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Yi-Fan Jiang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - John P Sheckelton
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Charles J Titus
- Department of Physics, Stanford University, Stanford, CA 94305, USA
| | - Suyin Grass Wang
- NSF's ChemMatCARS, Center for Advanced Radiation Sources, c/o Advanced Photon Source/ANL, The University of Chicago, Argonne, IL 60439, USA
| | - Yu-Sheng Chen
- NSF's ChemMatCARS, Center for Advanced Radiation Sources, c/o Advanced Photon Source/ANL, The University of Chicago, Argonne, IL 60439, USA
| | - Simon J Teat
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Adam A Aczel
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Guangyong Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102, USA
| | - Hong-Chen Jiang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Young S Lee
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
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18
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Suzuki T, Savary L, Liu JP, Lynn JW, Balents L, Checkelsky JG. Singular angular magnetoresistance in a magnetic nodal semimetal. Science 2019; 365:377-381. [PMID: 31221772 PMCID: PMC11131137 DOI: 10.1126/science.aat0348] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/07/2019] [Indexed: 05/30/2024]
Abstract
Transport coefficients of correlated electron systems are often useful for mapping hidden phases with distinct symmetries. Here we report a transport signature of spontaneous symmetry breaking in the magnetic Weyl semimetal cerium-aluminum-germanium (CeAlGe) system in the form of singular angular magnetoresistance (SAMR). This angular response exceeding 1000% per radian is confined along the high-symmetry axes with a full width at half maximum reaching less than 1° and is tunable via isoelectronic partial substitution of silicon for germanium. The SAMR phenomena is explained theoretically as a consequence of controllable high-resistance domain walls, arising from the breaking of magnetic point group symmetry strongly coupled to a nearly nodal electronic structure. This study indicates ingredients for engineering magnetic materials with high angular sensitivity by lattice and site symmetries.
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Affiliation(s)
- T Suzuki
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - L Savary
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA
- Université de Lyon, École Normale Supérieure de Lyon, Université Claude Bernard Lyon I, CNRS, Laboratoire de Physique, 46 Allée d'Italie, 69007 Lyon, France
| | - J-P Liu
- Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA
- Department of Physics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - J W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - L Balents
- Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA
| | - J G Checkelsky
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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19
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Smolyaninova VN, Lynn JW, Butch NP, Chen-Mayer H, Prestigiacomo JC, Osofsky MS, Smolyaninov II. Observation of plasmon-phonons in a metamaterial superconductor using inelastic neutron scattering. PHYSICAL REVIEW. B 2019; 100:10.1103/physrevb.100.024515. [PMID: 38845604 PMCID: PMC11155593 DOI: 10.1103/physrevb.100.024515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
A metamaterial approach is capable of drastically increasing the critical temperature,T c , of composite metal-dielectric superconductors as demonstrated by the tripling ofT c that was observed in bulk Al-Al2O3 coreshell metamaterials. A theoretical model based on the Maxwell-Garnett approximation provides a microscopic explanation of this effect in terms of electron-electron pairing mediated by a hybrid plasmon-phonon excitation. We report an observation of this excitation in Al-Al2O3 core-shell metamaterials using inelastic neutron scattering. This result provides support for this mechanism of superconductivity in metamaterials.
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Affiliation(s)
- Vera N Smolyaninova
- Department of Physics Astronomy and Geosciences, Towson University, 8000 York Rd., Towson, Maryland 21252, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Nicholas P Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Heather Chen-Mayer
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | | | - M S Osofsky
- Naval Research Laboratory, Washington, DC 20375, USA
| | - Igor I Smolyaninov
- Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742, USA
- Saltenna LLC, 1751 Pinnacle Drive #600 McLean, Virginia 22102, USA
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20
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Montfrooij W, Heitmann T, Qiu Y, Watson S, Erwin R, Chen W, Zhao Y, Aronson M, Huang Y, de Visser A. Quantum critical behavior in Ce(Fe 0.76Ru 0.24) 2Ge 2. PHYSICAL REVIEW. B 2019; 99:10.1103/PhysRevB.99.195113. [PMID: 38712021 PMCID: PMC11071051 DOI: 10.1103/physrevb.99.195113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Systems with embedded magnetic ions that exhibit a competition between magnetic order and disorder down to absolute zero can display unusual low-temperature behaviors of the resistivity, susceptibility, and specific heat. Moreover, the dynamic response of such a system can display hyperscaling behavior in which the relaxation back to equilibrium when an amount of energy E is given to the system at temperature T only depends on the ratio E / T . Ce(Fe0.755Ru0.245)2Ge2 is a system that displays these behaviors. We show that these complex behaviors are rooted in a fragmentation of the magnetic lattice upon cooling caused by a distribution of local Kondo screening temperatures, and that the hyperscaling behavior can be attributed to the flipping of the total magnetic moment of magnetic clusters that spontaneously form and order upon cooling. We present our arguments based on the review of two-decades worth of neutron scattering and transport data on this system, augmented with new polarized and unpolarized neutron scattering experiments.
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Affiliation(s)
- Wouter Montfrooij
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, USA
- Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211, USA
| | - Tom Heitmann
- Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211, USA
| | - Yiming Qiu
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Shannon Watson
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Ross Erwin
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Wangchun Chen
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Yang Zhao
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Meigan Aronson
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Yingkai Huang
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Anne de Visser
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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21
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Manley ME, Hellman O, Shulumba N, May AF, Stonaha PJ, Lynn JW, Garlea VO, Alatas A, Hermann RP, Budai JD, Wang H, Sales BC, Minnich AJ. Intrinsic anharmonic localization in thermoelectric PbSe. Nat Commun 2019; 10:1928. [PMID: 31028271 PMCID: PMC6486597 DOI: 10.1038/s41467-019-09921-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/05/2019] [Indexed: 11/22/2022] Open
Abstract
Lead chalcogenides have exceptional thermoelectric properties and intriguing anharmonic lattice dynamics underlying their low thermal conductivities. An ideal material for thermoelectric efficiency is the phonon glass-electron crystal, which drives research on strategies to scatter or localize phonons while minimally disrupting electronic-transport. Anharmonicity can potentially do both, even in perfect crystals, and simulations suggest that PbSe is anharmonic enough to support intrinsic localized modes that halt transport. Here, we experimentally observe high-temperature localization in PbSe using neutron scattering but find that localization is not limited to isolated modes - zero group velocity develops for a significant section of the transverse optic phonon on heating above a transition in the anharmonic dynamics. Arrest of the optic phonon propagation coincides with unusual sharpening of the longitudinal acoustic mode due to a loss of phase space for scattering. Our study shows how nonlinear physics beyond conventional anharmonic perturbations can fundamentally alter vibrational transport properties.
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Affiliation(s)
- M E Manley
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA.
| | - O Hellman
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA
| | - N Shulumba
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA
| | - A F May
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - P J Stonaha
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - J W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - V O Garlea
- Neutron Scattering Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - A Alatas
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 64039, USA
| | - R P Hermann
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - J D Budai
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - H Wang
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - B C Sales
- Material Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - A J Minnich
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA.
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22
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Rai BK, H. Oswald IW, Ban W, Huang CL, Loganathan V, Hallas AM, Wilson MN, Luke GM, Harriger L, Huang Q, Li Y, Dzsaber S, Chan JY, Wang NL, Paschen S, Lynn JW, Nevidomskyy AH, Dai P, Si Q, Morosan E. Low-carrier density and fragile magnetism in a Kondo lattice system. PHYSICAL REVIEW. B 2019; 99:10.1103/PhysRevB.99.085120. [PMID: 38487214 PMCID: PMC10938852 DOI: 10.1103/physrevb.99.085120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
Kondo-based semimetals and semiconductors are of extensive current interest as a viable platform for strongly correlated states in the dilute carrier limit. It is thus important to explore the routes to understand such systems. One established pathway is through the Kondo effect in metallic nonmagnetic analogs, in the so called half-filling case of one conduction electron and one 4f electron per site. Here, we demonstrate that Kondo-based semimetals develop out of conduction electrons with a low-carrier density in the presence of an even number of rare-earth sites. We do so by studying the Kondo material Yb3Ir4Ge13 along with its closed-4f -shell counterpart, Lu3Ir4Ge13. Through magnetotransport, optical conductivity, and thermodynamic measurements, we establish that the correlated semimetallic state of Yb3Ir4Ge13 below its Kondo temperature originates from the Kondo effect of a low-carrier conduction-electron background. In addition, it displays fragile magnetism at very low temperatures, which in turn, can be tuned to a Griffiths-phase-like regime through Lu-for-Yb substitution. These findings are connected with recent theoretical studies in simplified models. Our results can pave the way to exploring strong correlation physics in a semimetallic environment.
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Affiliation(s)
- Binod K. Rai
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - Iain W. H. Oswald
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080, USA
| | - Wenjing Ban
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - C.-L. Huang
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - V. Loganathan
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - A. M. Hallas
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada L8S 4M1
| | - M. N. Wilson
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada L8S 4M1
| | - G. M. Luke
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada L8S 4M1
- Canadian Institute for Advanced Research, 661 University Ave, Suite 505, Toronto, Ontario, Canada M5G 1M1
- TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., Canada V6T 2A3
| | - L. Harriger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Q. Huang
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Y. Li
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - Sami Dzsaber
- Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria
| | - Julia Y. Chan
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080, USA
| | - N. L. Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Silke Paschen
- Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria
| | - J. W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Andriy H. Nevidomskyy
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - Pengcheng Dai
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - Q. Si
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
| | - E. Morosan
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, Texas 77005, USA
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23
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Miao L, Basak R, Ran S, Xu Y, Kotta E, He H, Denlinger JD, Chuang YD, Zhao Y, Xu Z, Lynn JW, Jeffries JR, Saha SR, Giannakis I, Aynajian P, Kang CJ, Wang Y, Kotliar G, Butch NP, Wray LA. High temperature singlet-based magnetism from Hund's rule correlations. Nat Commun 2019; 10:644. [PMID: 30733441 PMCID: PMC6367396 DOI: 10.1038/s41467-019-08497-3] [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: 10/04/2018] [Accepted: 01/10/2019] [Indexed: 11/24/2022] Open
Abstract
Uranium compounds can manifest a wide range of fascinating many-body phenomena, and are often thought to be poised at a crossover between localized and itinerant regimes for 5f electrons. The antiferromagnetic dipnictide USb2 has been of recent interest due to the discovery of rich proximate phase diagrams and unusual quantum coherence phenomena. Here, linear-dichroic X-ray absorption and elastic neutron scattering are used to characterize electronic symmetries on uranium in USb2 and isostructural UBi2. Of these two materials, only USb2 is found to enable strong Hund’s rule alignment of local magnetic degrees of freedom, and to undergo distinctive changes in local atomic multiplet symmetry across the magnetic phase transition. Theoretical analysis reveals that these and other anomalous properties of the material may be understood by attributing it as the first known high temperature realization of a singlet ground state magnet, in which magnetism occurs through a process that resembles exciton condensation. Electrons in uranium-based materials are often on the border between localised and itinerant behaviour, which can lead to unusual magnetic behaviour. Here the authors combine experiment and theory to show that USb2 may be an unusually high temperature example of a singlet-ground-state magnet.
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Affiliation(s)
- Lin Miao
- Department of Physics, New York University, New York, NY, 10003, USA.,Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Rourav Basak
- Department of Physics, New York University, New York, NY, 10003, USA
| | - Sheng Ran
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Yishuai Xu
- Department of Physics, New York University, New York, NY, 10003, USA
| | - Erica Kotta
- Department of Physics, New York University, New York, NY, 10003, USA
| | - Haowei He
- Department of Physics, New York University, New York, NY, 10003, USA
| | - Jonathan D Denlinger
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yi-De Chuang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Y Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Z Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - J W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - J R Jeffries
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - S R Saha
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD, 20742, USA
| | - Ioannis Giannakis
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, 13902, USA
| | - Pegor Aynajian
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, 13902, USA
| | - Chang-Jong Kang
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, 08854-8019, USA
| | - Yilin Wang
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Gabriel Kotliar
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, 08854-8019, USA
| | - Nicholas P Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD, 20742, USA
| | - L Andrew Wray
- Department of Physics, New York University, New York, NY, 10003, USA.
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24
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Xue Z, Ramirez‐Cuesta AJ, Brown CM, Calder S, Cao H, Chakoumakos BC, Daemen LL, Huq A, Kolesnikov AI, Mamontov E, Podlesnyak AA, Wang X. Neutron Instruments for Research in Coordination Chemistry. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801076] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zi‐Ling Xue
- Department of Chemistry University of Tennessee 37996 Knoxville Tennessee United States
| | - Anibal J. Ramirez‐Cuesta
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Craig M. Brown
- Center for Neutron Research National Institute of Standards and Technology 20899 Gaithersburg Maryland United States
- Department of Chemical and Biomolecular Engineering University of Delaware 19716 Newark Delaware United States
| | - Stuart Calder
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Huibo Cao
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Bryan C. Chakoumakos
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Luke L. Daemen
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Ashfia Huq
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Alexander I. Kolesnikov
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Eugene Mamontov
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Andrey A. Podlesnyak
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Xiaoping Wang
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
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25
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Chapagain K, Brown DE, Kolesnik S, Lapidus S, Haberl B, Molaison J, Lin C, Kenney-Benson C, Park C, Pietosa J, Markiewicz E, Andrzejewski B, Lynn JW, Rosenkranz S, Dabrowski B, Chmaissem O. Tunable multiferroic order parameters in Sr 1- x Ba x Mn 1- y Ti y O 3. PHYSICAL REVIEW MATERIALS 2019; 3:https://doi.org/10.1103/PhysRevMaterials.3.084401. [PMID: 33134793 PMCID: PMC7594212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Responding to the rapidly increasing demand for efficient energy usage and increased speed and functionality of electronic and spintronic devices, multiferroic oxides have recently emerged as key materials capable of tackling this multifaceted challenge. In this paper, we describe the development of single-site manganese-based multiferroic perovskite materials with modest amounts of nonmagnetic Ti substituted at the magnetic Mn site in Sr1- x Ba x Mn1- y Ti y O3 (SBMTO). Significantly enhanced properties were achieved with ferroelectric-type structural transition temperatures boosted to ∼430K. Ferroelectric distortions with large spontaneous polarization values of ∼30μC/cm2, derived from a point charge model, are similar in magnitude to those of the prototypical nonmagnetic BaTiO3. Temperature dependence of the system's properties was investigated by synchrotron x-ray powder diffraction and neutron powder diffraction at ambient and high pressures. Various relationships were determined between the structural and magnetic properties, Ba and Ti contents, and T N and T C. Most importantly, our results demonstrate the large coupling between the magnetic and ferroelectric order parameters and the wide tunability of this coupling by slight variations of the material's stoichiometry.
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Affiliation(s)
- Kamal Chapagain
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
| | - Dennis E. Brown
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
| | - Stanislaw Kolesnik
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
| | - Saul Lapidus
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Bianca Haberl
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Jamie Molaison
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Chuanlong Lin
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
| | - Curtis Kenney-Benson
- HPCAT, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Changyong Park
- HPCAT, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Jaroslaw Pietosa
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Ewa Markiewicz
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, PL-60179 Poznań, Poland
| | - Bartlomiej Andrzejewski
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, PL-60179 Poznań, Poland
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
| | - Stephan Rosenkranz
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Bogdan Dabrowski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Omar Chmaissem
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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26
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Amplitude mode in the planar triangular antiferromagnet Na 0.9MnO 2. Nat Commun 2018; 9:2188. [PMID: 29872040 PMCID: PMC5988795 DOI: 10.1038/s41467-018-04601-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 05/11/2018] [Indexed: 11/11/2022] Open
Abstract
Amplitude modes arising from symmetry breaking in materials are of broad interest in condensed matter physics. These modes reflect an oscillation in the amplitude of a complex order parameter, yet are typically unstable and decay into oscillations of the order parameter’s phase. This renders stable amplitude modes rare, and exotic effects in quantum antiferromagnets have historically provided a realm for their detection. Here we report an alternate route to realizing amplitude modes in magnetic materials by demonstrating that an antiferromagnet on a two-dimensional anisotropic triangular lattice (α-Na0.9MnO2) exhibits a long-lived, coherent oscillation of its staggered magnetization field. Our results show that geometric frustration of Heisenberg spins with uniaxial single-ion anisotropy can renormalize the interactions of a dense two-dimensional network of moments into largely decoupled, one-dimensional chains that manifest a longitudinally polarized-bound state. This bound state is driven by the Ising-like anisotropy inherent to the Mn3+ ions of this compound. Oscillations of the order parameter amplitude in magnetically ordered materials provide condensed matter analogues of the Higgs boson but in most cases they are unstable. Dally et al. show that the quasi-one-dimensional magnet α-Na0.9MnO2 supports stable amplitude excitations.
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27
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Chen X, Hwang S, Chisnell R, Wang Y, Wu F, Kim S, Lynn JW, Su D, Li X. Reversible Flat to Rippling Phase Transition in Fe Containing Layered Battery Electrode Materials. ADVANCED FUNCTIONAL MATERIALS 2018; 28:https://doi.org/10.1002/adfm.201803896. [PMID: 32863818 PMCID: PMC7450722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Layered sodium transition metal oxides of NaTMO2 (TM = 3d transition metal) show unique capability to mix different compositions of Fe to the TM layer, a phenomenon that does not exist in LiTMO2. Here, a novel spontaneous TM layer rippling in the sodium ion battery cathode materials is reported, revealed by in situ X-ray diffraction, Cs-corrected scanning transmission electron microscopy, and density functional theory simulation, where the softening and distortion of FeO6 octahedra collectively drives the flat TM planes into rippled ones with inhomogeneous interlayer distance at high voltage. In such a rippling phase, charge and discharge of Na ions take different evolution pathways, resulting in an unusual hysteresis voltage loop. Importantly, upon discharge beyond a certain Na composition, the rippling TM layer will go back to flat, giving the reversibility of such structural evolution in the following cycles.
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Affiliation(s)
- Xi Chen
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Sooyeon Hwang
- Center for Functional Nanomaterials, Brookhaven National Laboratory Upton, NY 11973, USA
| | - Robin Chisnell
- NIST Center for Neutron Research, National Institute of Standards and Technology Gaithersburg, MD 20899, USA
| | - Yichao Wang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Fan Wu
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Sooran Kim
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology Gaithersburg, MD 20899, USA
| | - Dong Su
- Center for Functional Nanomaterials, Brookhaven National Laboratory Upton, NY 11973, USA
| | - Xin Li
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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28
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Chen X, Wang Y, Wiaderek K, Sang X, Borkiewicz O, Chapman K, LeBeau J, Lynn J, Li X. Super Charge Separation and High Voltage Phase in Na x MnO 2. ADVANCED FUNCTIONAL MATERIALS 2018; 28:https://doi.org/10.1002/adfm.201805105. [PMID: 33132799 PMCID: PMC7594259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Na x MnO2 shows Mn3+ and Mn4+ charge separation with the charge stripe ordering upon Na deintercalation at x = 5/8. In this paper it is shown that, surprisingly, at lower Na compositions of 5/8 > x ≥ 1/18 the phase evolution pathway of Na x MnO2 upon Na deintercalation shows a unique phenomenon of super charge separation, where the Mn3+ and Mn4+ ions fully charge-separate into charge superplanes formed by succession of charge stripes in the third dimension. The Mn3+ superplanes attract Na ions electronically, and dominate the antiferromagnetic interactions in NaMnO2. Na ions in Mn3+ superplanes also naturally pillar the MnO2 layers to form the unusual O1 phases with large interlayer distances at x < 1/3, which dominates the unique electrochemical behavior of NaMnO2.
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Affiliation(s)
- Xi Chen
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Yichao Wang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Kamila Wiaderek
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Xiahan Sang
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Olaf Borkiewicz
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Karena Chapman
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - James LeBeau
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Jeffrey Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Xin Li
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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29
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Sumirat I, Ramadhani A, Bharoto B, Sairun S, Refai M, Santoso E, Putra M. A. M. BATAN’s thermal neutron TAS: First results. JOURNAL OF NEUTRON RESEARCH 2017. [DOI: 10.3233/jnr-170039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Iwan Sumirat
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
| | - A. Ramadhani
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
| | - B. Bharoto
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
| | - S. Sairun
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
| | - M. Refai
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
| | - E. Santoso
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
| | - Muzakkiy Putra M. A.
- Neutron Beam Technology Division – BTBN, Center for Science and Technology of Advanced Materials – PSTBM, National Nuclear Energy Agency – BATAN, Gedung 40 BATAN, Kawasan Puspiptek Setu Tangerang Selatan, Banten, Indonesia, 15314
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30
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Gitgeatpong G, Zhao Y, Piyawongwatthana P, Qiu Y, Harriger LW, Butch NP, Sato TJ, Matan K. Nonreciprocal Magnons and Symmetry-Breaking in the Noncentrosymmetric Antiferromagnet. PHYSICAL REVIEW LETTERS 2017; 119:047201. [PMID: 29341758 DOI: 10.1103/physrevlett.119.047201] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Indexed: 06/07/2023]
Abstract
Inelastic neutron scattering measurements were performed to study spin dynamics in the noncentrosymmetric antiferromagnet α-Cu_{2}V_{2}O_{7}. For the first time, nonreciprocal magnons were experimentally measured in an antiferromagnet. These nonreciprocal magnons are caused by the incompatibility between anisotropic exchange and antisymmetric Dzyaloshinskii-Moriya interactions, which arise from broken symmetry, resulting in a collinear ordered state but helical spin dynamics. The nonreciprocity introduces the difference in the phase velocity of the counterrotating modes, causing the opposite spontaneous magnonic Faraday rotation of the left- and right-propagating spin waves. The breaking of spatial inversion and time reversal symmetry is revealed as a magnetic-field-induced asymmetric energy shift, which provides a test for the detailed balance relation.
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Affiliation(s)
- G Gitgeatpong
- Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- ThEP, Commission of Higher Education, Bangkok 10400, Thailand
- Department of Physics, Faculty of Science and Technology, Phranakhon Rajabhat University, Bangkok 10220, Thailand
| | - Y Zhao
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - P Piyawongwatthana
- Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Y Qiu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - L W Harriger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - N P Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - T J Sato
- IMRAM, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - K Matan
- Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- ThEP, Commission of Higher Education, Bangkok 10400, Thailand
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31
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Lee CH, Wang CW, Zhao Y, Li WH, Lynn JW, Harris AB, Rule K, Yang HD, Berger H. Complex magnetic incommensurability and electronic charge transfer through the ferroelectric transition in multiferroic Co 3TeO 6. Sci Rep 2017; 7:6437. [PMID: 28743893 PMCID: PMC5527072 DOI: 10.1038/s41598-017-06651-9] [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: 03/24/2017] [Accepted: 06/14/2017] [Indexed: 11/09/2022] Open
Abstract
Polarized and unpolarized neutron diffractions have been carried out to investigate the nature of the magnetic structures and transitions in monoclinic Co3TeO6. As the temperature is lowered below 26 K long range order develops, which is fully incommensurate (ICM) in all three crystallographic directions. Below 19.5 K additional commensurate magnetic peaks develop, consistent with the Γ4 irreducible representation, along with a splitting of the ICM peaks along the h direction which indicates that there are two separate sets of magnetic modulation vectors. Below 18 K, this small additional magnetic incommensurability disappears, ferroelectricity develops, an additional commensurate magnetic structure consistent with Γ3 irreducible representation appears, and the k component of the ICM wave vector disappears. Synchrotron x-ray diffraction measurements demonstrate that there is a significant shift of the electronic charge distribution from the Te ions at the crystallographic 8 f sites to the neighboring Co and O ions. These results, together with the unusually small electric polarization, its strong magnetic field dependence, and the negative thermal expansion in all three lattice parameters, suggest this material is an antiferroelectric. Below15 K the k component of the ICM structure reappears, along with second-order ICM Bragg peaks, which polarized neutron data demonstrate are magnetic in origin.
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Affiliation(s)
- Chi-Hung Lee
- Department of Physics, National Central University, Jhongli, 32001, Taiwan
| | - Chin-Wei Wang
- Neutron Group, National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899, USA.,Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Wen-Hsien Li
- Department of Physics, National Central University, Jhongli, 32001, Taiwan.
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899, USA
| | - A Brooks Harris
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kirrily Rule
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - Hung-Duen Yang
- Department of Physics and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Helmuth Berger
- Institute of Physics of Complex Matter, EPFL, Lausanne, Switzerland
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32
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Manley ME, Abernathy DL, Sahul R, Parshall DE, Lynn JW, Christianson AD, Stonaha PJ, Specht ED, Budai JD. Giant electromechanical coupling of relaxor ferroelectrics controlled by polar nanoregion vibrations. SCIENCE ADVANCES 2016; 2:e1501814. [PMID: 27652338 PMCID: PMC5026422 DOI: 10.1126/sciadv.1501814] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
Relaxor-based ferroelectrics are prized for their giant electromechanical coupling and have revolutionized sensor and ultrasound applications. A long-standing challenge for piezoelectric materials has been to understand how these ultrahigh electromechanical responses occur when the polar atomic displacements underlying the response are partially broken into polar nanoregions (PNRs) in relaxor-based ferroelectrics. Given the complex inhomogeneous nanostructure of these materials, it has generally been assumed that this enhanced response must involve complicated interactions. By using neutron scattering measurements of lattice dynamics and local structure, we show that the vibrational modes of the PNRs enable giant coupling by softening the underlying macrodomain polarization rotations in relaxor-based ferroelectric PMN-xPT {(1 - x)[Pb(Mg1/3Nb2/3)O3] - xPbTiO3} (x = 30%). The mechanism involves the collective motion of the PNRs with transverse acoustic phonons and results in two hybrid modes, one softer and one stiffer than the bare acoustic phonon. The softer mode is the origin of macroscopic shear softening. Furthermore, a PNR mode and a component of the local structure align in an electric field; this further enhances shear softening, revealing a way to tune the ultrahigh piezoelectric response by engineering elastic shear softening.
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Affiliation(s)
- Michael E. Manley
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Douglas L. Abernathy
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Raffi Sahul
- TRS Technologies, State College, PA 16801, USA
| | - Daniel E. Parshall
- NIST Center for Neutron Research, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Andrew D. Christianson
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Paul J. Stonaha
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Eliot D. Specht
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - John D. Budai
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Wu LS, Gannon WJ, Zaliznyak IA, Tsvelik AM, Brockmann M, Caux JS, Kim MS, Qiu Y, Copley JRD, Ehlers G, Podlesnyak A, Aronson MC. Orbital-exchange and fractional quantum number excitations in an f-electron metal, Yb2Pt2Pb. Science 2016; 352:1206-10. [DOI: 10.1126/science.aaf0981] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 04/29/2016] [Indexed: 11/02/2022]
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Takatsu H, Onoda S, Kittaka S, Kasahara A, Kono Y, Sakakibara T, Kato Y, Fåk B, Ollivier J, Lynn JW, Taniguchi T, Wakita M, Kadowaki H. Quadrupole Order in the Frustrated Pyrochlore Tb_{2+x}Ti_{2-x}O_{7+y}. PHYSICAL REVIEW LETTERS 2016; 116:217201. [PMID: 27284670 DOI: 10.1103/physrevlett.116.217201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 06/06/2023]
Abstract
A hidden order that emerges in the frustrated pyrochlore Tb_{2+x}Ti_{2-x}O_{7+y} with T_{c}=0.53 K is studied using specific heat, magnetization, and neutron scattering experiments on a high-quality single crystal. Semiquantitative analyses based on a pseudospin-1/2 Hamiltonian for ionic non-Kramers magnetic doublets demonstrate that it is an ordered state of electric quadrupole moments. The elusive spin liquid state of the nominal Tb_{2}Ti_{2}O_{7} is most likely a U(1) quantum spin-liquid state.
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Affiliation(s)
- H Takatsu
- Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - S Onoda
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - S Kittaka
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - A Kasahara
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Y Kono
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - T Sakakibara
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Y Kato
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
| | - B Fåk
- Institute Laue Langevin, BP 156, F-38042 Grenoble, France
| | - J Ollivier
- Institute Laue Langevin, BP 156, F-38042 Grenoble, France
| | - J W Lynn
- NCNR, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
| | - T Taniguchi
- Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan
| | - M Wakita
- Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan
| | - H Kadowaki
- Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan
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35
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An itinerant antiferromagnetic metal without magnetic constituents. Nat Commun 2015; 6:7701. [PMID: 26166042 PMCID: PMC4510670 DOI: 10.1038/ncomms8701] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 06/02/2015] [Indexed: 11/17/2022] Open
Abstract
The origin of magnetism in metals has been traditionally discussed in two diametrically opposite limits: itinerant and local moments. Surprisingly, there are very few known examples of materials that are close to the itinerant limit, and their properties are not universally understood. In the case of the two such examples discovered several decades ago, the itinerant ferromagnets ZrZn2 and Sc3In, the understanding of their magnetic ground states draws on the existence of 3d electrons subject to strong spin fluctuations. Similarly, in Cr, an elemental itinerant antiferromagnet with a spin density wave ground state, its 3d electron character has been deemed crucial to it being magnetic. Here, we report evidence for an itinerant antiferromagnetic metal with no magnetic constituents: TiAu. Antiferromagnetic order occurs below a Néel temperature of 36 K, about an order of magnitude smaller than in Cr, rendering the spin fluctuations in TiAu more important at low temperatures. This itinerant antiferromagnet challenges the currently limited understanding of weak itinerant antiferromagnetism, while providing insights into the effects of spin fluctuations in itinerant–electron systems. Sc3In and ZrZn2 are the only two known itinerant ferromagnets that form from non-magnetic constituents. Now, Svanidze et al., evidence itinerant antiferromagnetism in TiAu below 36 K using thermodynamic, transport, muon-based and neutron-based measurements, and density functional analysis.
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36
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Nakajima Y, Hu R, Kirshenbaum K, Hughes A, Syers P, Wang X, Wang K, Wang R, Saha SR, Pratt D, Lynn JW, Paglione J. Topological RPdBi half-Heusler semimetals: A new family of noncentrosymmetric magnetic superconductors. SCIENCE ADVANCES 2015; 1:e1500242. [PMID: 26601201 PMCID: PMC4640617 DOI: 10.1126/sciadv.1500242] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 04/13/2015] [Indexed: 05/21/2023]
Abstract
We report superconductivity and magnetism in a new family of topological semimetals, the ternary half-Heusler compound RPdBi (R: rare earth). In this series, tuning of the rare earth f-electron component allows for simultaneous control of both lattice density via lanthanide contraction and the strength of magnetic interaction via de Gennes scaling, allowing for a unique tuning of the normal-state band inversion strength, superconducting pairing, and magnetically ordered ground states. Antiferromagnetism with ordering vector (½,½,½) occurs below a Néel temperature that scales with de Gennes factor dG, whereas a superconducting transition is simultaneously supressed with increasing dG. With superconductivity appearing in a system with noncentrosymmetric crystallographic symmetry, the possibility of spin-triplet Cooper pairing with nontrivial topology analogous to that predicted for the normal-state electronic structure provides a unique and rich opportunity to realize both predicted and new exotic excitations in topological materials.
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Affiliation(s)
- Yasuyuki Nakajima
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Rongwei Hu
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Kevin Kirshenbaum
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Alex Hughes
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Paul Syers
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Xiangfeng Wang
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Kefeng Wang
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Renxiong Wang
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Shanta R. Saha
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Daniel Pratt
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jeffrey W. Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Johnpierre Paglione
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
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37
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Zhang Q, Fernandes RM, Lamsal J, Yan J, Chi S, Tucker GS, Pratt DK, Lynn JW, McCallum RW, Canfield PC, Lograsso TA, Goldman AI, Vaknin D, McQueeney RJ. Neutron-scattering measurements of spin excitations in LaFeAsO and Ba(Fe(0.953)Co(0.047))(2)As(2): evidence for a sharp enhancement of spin fluctuations by nematic order. PHYSICAL REVIEW LETTERS 2015; 114:057001. [PMID: 25699463 DOI: 10.1103/physrevlett.114.057001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Indexed: 06/04/2023]
Abstract
Inelastic neutron scattering is employed to investigate the impact of electronic nematic order on the magnetic spectra of LaFeAsO and Ba(Fe(0.953)Co(0.047))(2)As(2). These materials are ideal to study the paramagnetic-nematic state, since the nematic order, signaled by the tetragonal-to-orthorhombic transition at T(S), sets in well above the stripe antiferromagnetic ordering at T(N). We find that the temperature-dependent dynamic susceptibility displays an anomaly at T(S) followed by a sharp enhancement in the spin-spin correlation length, revealing a strong feedback effect of nematic order on the low-energy magnetic spectrum. Our findings can be consistently described by a model that attributes the structural or nematic transition to magnetic fluctuations, and unveils the key role played by nematic order in promoting the long-range stripe antiferromagnetic order in iron pnictides.
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Affiliation(s)
- Qiang Zhang
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Rafael M Fernandes
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Jagat Lamsal
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Jiaqiang Yan
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Songxue Chi
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Gregory S Tucker
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Daniel K Pratt
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
| | - R W McCallum
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Paul C Canfield
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Thomas A Lograsso
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Alan I Goldman
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - David Vaknin
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Robert J McQueeney
- Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA and Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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38
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Xu Z, Stock C, Chi S, Kolesnikov AI, Xu G, Gu G, Tranquada JM. Neutron-scattering evidence for a periodically modulated superconducting phase in the underdoped cuprate La1.905Ba0.095CuO4. PHYSICAL REVIEW LETTERS 2014; 113:177002. [PMID: 25379931 DOI: 10.1103/physrevlett.113.177002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Indexed: 06/04/2023]
Abstract
The role of antiferromagnetic spin correlations in high-temperature superconductors remains a matter of debate. We present inelastic neutron-scattering evidence that gapless spin fluctuations coexist with superconductivity in La1.905Ba0.095CuO4. Furthermore, we observe that both the low-energy magnetic spectral weight and the spin incommensurability are enhanced with the onset of superconducting correlations. We propose that the coexistence occurs through intertwining of spatial modulations of the pair wave function and the antiferromagnetic correlations. This proposal is also directly relevant to sufficiently underdoped La(2-x)Sr(x)CuO(4) and YBa(2)Cu(3)O(6+x).
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Affiliation(s)
- Zhijun Xu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - C Stock
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Songxue Chi
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - A I Kolesnikov
- Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Guangyong Xu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - Genda Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - J M Tranquada
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
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Pintschovius L, Reznik D, Weber F, Bourges P, Parshall D, Mittal R, Chaplot SL, Heid R, Wolf T, Lamago D, Lynn JW. Spurious peaks arising from multiple scattering events involving the sample environment in inelastic neutron scattering. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576714010140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Well defined peaks with energies of about 18 meV have been observed in a variety of inelastic neutron scattering experiments on both single crystals and powders, using either the triple-axis or the time-of-flight technique. They can easily be mistaken for signatures of real excitations. It has been found that they are due to multiple scattering events involving primarily the walls of the sample environment. Hence, they are particularly troublesome in experiments using very small samples, as have been used with recently developed high-intensity neutron spectrometers. Measures required to reduce the unwanted scattering to a minimum are also discussed.
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40
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Li X, Ma X, Su D, Liu L, Chisnell R, Ong SP, Chen H, Toumar A, Idrobo JC, Lei Y, Bai J, Wang F, Lynn JW, Lee YS, Ceder G. Direct visualization of the Jahn-Teller effect coupled to Na ordering in Na5/8MnO2. NATURE MATERIALS 2014; 13:586-592. [PMID: 24836735 DOI: 10.1038/nmat3964] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 03/28/2014] [Indexed: 06/03/2023]
Abstract
The cooperative Jahn-Teller effect (CJTE) refers to the correlation of distortions arising from individual Jahn-Teller centres in complex compounds. The effect usually induces strong coupling between the static or dynamic charge, orbital and magnetic ordering, which has been related to many important phenomena such as colossal magnetoresistance and superconductivity. Here we report a Na5/8MnO2 superstructure with a pronounced static CJTE that is coupled to an unusual Na vacancy ordering. We visualize this coupled distortion and Na ordering down to the atomic scale. The Mn planes are periodically distorted by a charge modulation on the Mn stripes, which in turn drives an unusually large displacement of some Na ions through long-ranged Na-O-Mn(3+)-O-Na interactions into a highly distorted octahedral site. At lower temperatures, magnetic order appears, in which Mn atomic stripes with different magnetic couplings are interwoven with each other. Our work demonstrates the strong interaction between alkali ordering, displacement, and electronic and magnetic structure, and underlines the important role that structural details play in determining electronic behaviour.
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Affiliation(s)
- Xin Li
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Xiaohua Ma
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Dong Su
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Lei Liu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Robin Chisnell
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Shyue Ping Ong
- 1] Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA [2]
| | - Hailong Chen
- 1] Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA [2]
| | - Alexandra Toumar
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Juan-Carlos Idrobo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Yuechuan Lei
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jianming Bai
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Feng Wang
- Sustainable Energy Technologies Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Young S Lee
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Gerbrand Ceder
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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41
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Phonon localization drives polar nanoregions in a relaxor ferroelectric. Nat Commun 2014; 5:3683. [PMID: 24718289 DOI: 10.1038/ncomms4683] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 03/18/2014] [Indexed: 11/08/2022] Open
Abstract
Relaxor ferroelectrics exemplify a class of functional materials where interplay between disorder and phase instability results in inhomogeneous nanoregions. Although known for about 30 years, there is no definitive explanation for polar nanoregions (PNRs). Here we show that ferroelectric phonon localization drives PNRs in relaxor ferroelectric PMN-30%PT using neutron scattering. At the frequency of a preexisting resonance mode, nanoregions of standing ferroelectric phonons develop with a coherence length equal to one wavelength and the PNR size. Anderson localization of ferroelectric phonons by resonance modes explains our observations and, with nonlinear slowing, the PNRs and relaxor properties. Phonon localization at additional resonances near the zone edges explains competing antiferroelectric distortions known to occur at the zone edges. Our results indicate the size and shape of PNRs that are not dictated by complex structural details, as commonly assumed, but by phonon resonance wave vectors. This discovery could guide the design of next generation relaxor ferroelectrics.
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Pandey A, Ueland BG, Yeninas S, Kreyssig A, Sapkota A, Zhao Y, Helton JS, Lynn JW, McQueeney RJ, Furukawa Y, Goldman AI, Johnston DC. Coexistence of half-metallic itinerant ferromagnetism with local-moment antiferromagnetism in Ba0.60K0.40Mn2As2. PHYSICAL REVIEW LETTERS 2013; 111:047001. [PMID: 23931395 DOI: 10.1103/physrevlett.111.047001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Indexed: 06/02/2023]
Abstract
Magnetization, nuclear magnetic resonance, high-resolution x-ray diffraction, and magnetic field-dependent neutron diffraction measurements reveal a novel magnetic ground state of Ba0.60K0.40Mn2As2 in which itinerant ferromagnetism (FM) below a Curie temperature TC≈100 K arising from the doped conduction holes coexists with collinear antiferromagnetism (AFM) of the Mn local moments that order below a Néel temperature TN=480 K. The FM ordered moments are aligned in the tetragonal ab plane and are orthogonal to the AFM ordered Mn moments that are aligned along the c axis. The magnitude and nature of the low-T FM ordered moment correspond to complete polarization of the doped-hole spins (half-metallic itinerant FM) as deduced from magnetization and ab-plane electrical resistivity measurements.
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Affiliation(s)
- Abhishek Pandey
- Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
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