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Huang Q, Rawl R, Xie WW, Chou ES, Zapf VS, Ding XX, Mauws C, Wiebe CR, Feng EX, Cao HB, Tian W, Ma J, Qiu Y, Butch N, Zhou HD. Non-magnetic ion site disorder effects on the quantum magnetism of a spin-1/2 equilateral triangular lattice antiferromagnet. J Phys Condens Matter 2022; 34:205401. [PMID: 35189602 DOI: 10.1088/1361-648x/ac5703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
With the motivation to study how non-magnetic ion site disorder affects the quantum magnetism of Ba3CoSb2O9, a spin-1/2 equilateral triangular lattice antiferromagnet, we performed DC and AC susceptibility, specific heat, elastic and inelastic neutron scattering measurements on single crystalline samples of Ba2.87Sr0.13CoSb2O9with Sr doping on non-magnetic Ba2+ion sites. The results show that Ba2.87Sr0.13CoSb2O9exhibits (i) a two-step magnetic transition at 2.7 K and 3.3 K, respectively; (ii) a possible canted 120 degree spin structure at zero field with reduced ordered moment as 1.24μB/Co; (iii) a series of spin state transitions for bothH∥ab-plane andH∥c-axis. ForH∥ab-plane, the magnetization plateau feature related to the up-up-down phase is significantly suppressed; (iv) an inelastic neutron scattering spectrum with only one gapped mode at zero field, which splits to one gapless and one gapped mode at 9 T. All these features are distinctly different from those observed for the parent compound Ba3CoSb2O9, which demonstrates that the non-magnetic ion site disorder (the Sr doping) plays a complex role on the magnetic properties beyond the conventionally expected randomization of the exchange interactions. We propose the additional effects including the enhancement of quantum spin fluctuations and introduction of a possible spatial anisotropy through the local structural distortions.
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Affiliation(s)
- Q Huang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
| | - R Rawl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
| | - W W Xie
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, United States of America
| | - E S Chou
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, United States of America
| | - V S Zapf
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America
| | - X X Ding
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America
| | - C Mauws
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - C R Wiebe
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba R3B 2E9, Canada
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - E X Feng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - W Tian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - J Ma
- Laboratory of Artificial Structures and Quantum Control, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang, People's Republic of China
| | - Y Qiu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America
| | - N Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America
| | - H D Zhou
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, United States of America
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2
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Tian W, Fishman RS, Cao HB, Sala G, Pajerowski DM, Garlea VO, Hong T, Daemen LL, Cheng YQ, Fernandez-Baca JA. IInvestigating the nature of the magnetoelectric coupling in molecular (ND4)2[FeCl5(D2O)] via neutron scattering studies. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321094599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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3
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Liu JY, Yu J, Ning JL, Yi HM, Miao L, Min LJ, Zhao YF, Ning W, Lopez KA, Zhu YL, Pillsbury T, Zhang YB, Wang Y, Hu J, Cao HB, Chakoumakos BC, Balakirev F, Weickert F, Jaime M, Lai Y, Yang K, Sun JW, Alem N, Gopalan V, Chang CZ, Samarth N, Liu CX, McDonald RD, Mao ZQ. Spin-valley locking and bulk quantum Hall effect in a noncentrosymmetric Dirac semimetal BaMnSb 2. Nat Commun 2021; 12:4062. [PMID: 34210963 PMCID: PMC8249485 DOI: 10.1038/s41467-021-24369-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
Spin-valley locking in monolayer transition metal dichalcogenides has attracted enormous interest, since it offers potential for valleytronic and optoelectronic applications. Such an exotic electronic state has sparsely been seen in bulk materials. Here, we report spin-valley locking in a Dirac semimetal BaMnSb2. This is revealed by comprehensive studies using first principles calculations, tight-binding and effective model analyses, angle-resolved photoemission spectroscopy measurements. Moreover, this material also exhibits a stacked quantum Hall effect (QHE). The spin-valley degeneracy extracted from the QHE is close to 2. This result, together with the Landau level spin splitting, further confirms the spin-valley locking picture. In the extreme quantum limit, we also observed a plateau in the z-axis resistance, suggestive of a two-dimensional chiral surface state present in the quantum Hall state. These findings establish BaMnSb2 as a rare platform for exploring coupled spin and valley physics in bulk single crystals and accessing 3D interacting topological states.
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Affiliation(s)
- J Y Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, USA
- Department of Physics and Astronomy, University of California, Irvine, CA, USA
| | - J Yu
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
- Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD, USA
| | - J L Ning
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, USA
| | - H M Yi
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - L Miao
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - L J Min
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Y F Zhao
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - W Ning
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - K A Lopez
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Y L Zhu
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - T Pillsbury
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - Y B Zhang
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, USA
| | - Y Wang
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - J Hu
- Department of Physics, University of Arkansas, Fayetteville, AR, USA
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - B C Chakoumakos
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - F Balakirev
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - F Weickert
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - M Jaime
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Y Lai
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Kun Yang
- Physics Department and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - J W Sun
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, USA
| | - N Alem
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - V Gopalan
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - C Z Chang
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - N Samarth
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
| | - C X Liu
- Department of Physics, The Pennsylvania State University, University Park, PA, USA.
| | - R D McDonald
- Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Z Q Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, USA.
- Department of Physics, The Pennsylvania State University, University Park, PA, USA.
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA.
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4
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Coates L, Cao HB, Chakoumakos BC, Frontzek MD, Hoffmann C, Kovalevsky AY, Liu Y, Meilleur F, Dos Santos AM, Myles DAA, Wang XP, Ye F. A suite-level review of the neutron single-crystal diffraction instruments at Oak Ridge National Laboratory. Rev Sci Instrum 2018; 89:092802. [PMID: 30278686 DOI: 10.1063/1.5030896] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
The nascent suite of single-crystal neutron diffractometers at the Oak Ridge National Laboratory has no equal at any other neutron scattering facility worldwide and offers the potential to re-assert single-crystal diffraction using neutrons as a significant tool to study nuclear and magnetic structures of small unit cell crystals, nuclear structures of macromolecules, and diffuse scattering. Signature applications and features of single-crystal neutron diffraction are high resolution nuclear structure analysis, magnetic structure and spin density determinations, contrast variation (particularly D2O/H2O) for nuclear structural studies, lack of radiation damage when using crystals of biological molecules such as proteins, and the fidelity to measure nuclear and magnetic diffuse scattering with elastic discrimination.
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Affiliation(s)
- L Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - B C Chakoumakos
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - M D Frontzek
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - C Hoffmann
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - A Y Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - Y Liu
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - F Meilleur
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - A M Dos Santos
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - D A A Myles
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - X P Wang
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - F Ye
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
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5
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Kamiya Y, Ge L, Hong T, Qiu Y, Quintero-Castro DL, Lu Z, Cao HB, Matsuda M, Choi ES, Batista CD, Mourigal M, Zhou HD, Ma J. Author Correction: The nature of spin excitations in the one-third magnetization plateau phase of Ba 3CoSb 2O 9. Nat Commun 2018; 9:3110. [PMID: 30068947 PMCID: PMC6070534 DOI: 10.1038/s41467-018-05679-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Y Kamiya
- Condensed Matter Theory Laboratory, RIKEN, Wako, 351-0198, Saitama, Japan.
| | - L Ge
- School of Physics, Georgia Institute of Technology, 30332, Atlanta, GA, USA
| | - Tao Hong
- Neutron Scattering Division, Oak Ridge National Laboratory, 37831, Oak Ridge, TN, USA
| | - Y Qiu
- NIST Centre for Neutron Research, National Institute of Standards and Technology, 20899, Gaithersburg, MD, USA
| | - D L Quintero-Castro
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109, Berlin, Germany
| | - Z Lu
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109, Berlin, Germany
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, 37831, Oak Ridge, TN, USA
| | - M Matsuda
- Neutron Scattering Division, Oak Ridge National Laboratory, 37831, Oak Ridge, TN, USA
| | - E S Choi
- National High Magnetic Field Laboratory, Florida State University, 32310, Tallahassee, FL, USA
| | - C D Batista
- Department of Physics and Astronomy, University of Tennessee, 37996, Knoxville, TN, USA.,Neutron Scattering Division and Shull-Wollan Center, Oak Ridge National Laboratory, 37831, Oak Ridge, TN, USA
| | - M Mourigal
- School of Physics, Georgia Institute of Technology, 30332, Atlanta, GA, USA
| | - H D Zhou
- National High Magnetic Field Laboratory, Florida State University, 32310, Tallahassee, FL, USA.,Department of Physics and Astronomy, University of Tennessee, 37996, Knoxville, TN, USA
| | - J Ma
- Department of Physics and Astronomy, University of Tennessee, 37996, Knoxville, TN, USA. .,Key Laboratory of Artificial Structures and Quantum Control, Department of Physics and Astronomy, Shanghai Jiao Tong University, 200240, Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, Jiangsu, China.
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6
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Kamiya Y, Ge L, Hong T, Qiu Y, Quintero-Castro DL, Lu Z, Cao HB, Matsuda M, Choi ES, Batista CD, Mourigal M, Zhou HD, Ma J. The nature of spin excitations in the one-third magnetization plateau phase of Ba 3CoSb 2O 9. Nat Commun 2018; 9:2666. [PMID: 29991805 PMCID: PMC6039502 DOI: 10.1038/s41467-018-04914-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 05/21/2018] [Indexed: 11/25/2022] Open
Abstract
Magnetization plateaus in quantum magnets—where bosonic quasiparticles crystallize into emergent spin superlattices—are spectacular yet simple examples of collective quantum phenomena escaping classical description. While magnetization plateaus have been observed in a number of spin-1/2 antiferromagnets, the description of their magnetic excitations remains an open theoretical and experimental challenge. Here, we investigate the dynamical properties of the triangular-lattice spin-1/2 antiferromagnet Ba3CoSb2O9 in its one-third magnetization plateau phase using a combination of nonlinear spin-wave theory and neutron scattering measurements. The agreement between our theoretical treatment and the experimental data demonstrates that magnons behave semiclassically in the plateau in spite of the purely quantum origin of the underlying magnetic structure. This allows for a quantitative determination of Ba3CoSb2O9 exchange parameters. We discuss the implication of our results to the deviations from semiclassical behavior observed in zero-field spin dynamics of the same material and conclude they must have an intrinsic origin. Frustrated magnetic materials attract significant interest because their properties can become dominated by quantum fluctuations. Here the authors show that excitations in the plateau phase of a quantum magnet can be understood semiclassically even though the ground state involves strong quantum effects.
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Affiliation(s)
- Y Kamiya
- Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama, 351-0198, Japan.
| | - L Ge
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Tao Hong
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Y Qiu
- NIST Centre for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - D L Quintero-Castro
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109, Berlin, Germany
| | - Z Lu
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109, Berlin, Germany
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - M Matsuda
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - E S Choi
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - C D Batista
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.,Neutron Scattering Division and Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - M Mourigal
- School of Physics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - H D Zhou
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA.,Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - J Ma
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA. .,Key Laboratory of Artificial Structures and Quantum Control, Department of Physics and Astronomy, Shanghai Jiao Tong University, 200240, Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, Jiangsu, China.
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7
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Yan JQ, Ochi M, Cao HB, Saparov B, Cheng JG, Uwatoko Y, Arita R, Sales BC, Mandrus DG. Magnetic order of Nd 5Pb 3 single crystals. J Phys Condens Matter 2018; 30:135801. [PMID: 29443004 DOI: 10.1088/1361-648x/aaaf3e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report millimeter-sized Nd5Pb3 single crystals grown out of a Nd-Co flux. We experimentally study the magnetic order of Nd5Pb3 single crystals by measuring the anisotropic magnetic properties, electrical resistivity under high pressure up to 8 GPa, specific heat, and neutron single crystal diffraction. Two successive magnetic orders are observed at T N1 = 44 K and T N2 = 8 K. The magnetic cells can be described with a propagation vector [Formula: see text]. Cooling below T N1, Nd1 and Nd3 order forming ferromagnetic stripes along the b-axis, and the ferromagnetic stripes are coupled antiferromagnetically along the a-axis for the [Formula: see text] magnetic domain. Cooling below T N2, Nd2 orders antiferromagnetically to nearby Nd3 ions. All ordered moments align along the crystallographic c-axis. The magnetic order at T N1 is accompanied by a quick drop of electrical resistivity upon cooling and a lambda-type anomaly in the temperature dependence of specific heat. At T N2, no anomaly was observed in electrical resistivity but there is a weak feature in specific heat. The resistivity measurements under hydrostatic pressures up to 8 GPa suggest a possible phase transition around 6 GPa. Our first-principles band structure calculations show that Nd5Pb3 has the same electronic structure as does Y5Si3 which has been reported to be a one-dimensional electride with anionic electrons that do not belong to any atom. Our study suggests that R 5Pb3 (R = rare earth) can be a materials playground for the study of magnetic electrides. This deserves further study after experimental confirmation of the presence of anionic electrons.
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Affiliation(s)
- J-Q Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America. Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, United States of America
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8
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Zhu M, Li PG, Wang Y, Cao HB, Tian W, Zhang HD, Phelan BD, Mao ZQ, Ke X. Temperature- and field-driven spin reorientations in triple-layer ruthenate Sr 4Ru 3O 10. Sci Rep 2018; 8:3914. [PMID: 29500391 PMCID: PMC5834612 DOI: 10.1038/s41598-018-22247-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/20/2018] [Indexed: 11/10/2022] Open
Abstract
Sr4Ru3O10, the n = 3 member of the Ruddlesden-Popper type ruthenate Srn+1RunO3n+1, is known to exhibit a peculiar metamagnetic transition in an in-plane magnetic field. However, the nature of both the temperature- and field-dependent phase transitions remains as a topic of debate. Here, we have investigated the magnetic transitions of Sr4Ru3O10 via single-crystal neutron diffraction measurements. At zero field, we find that the system undergoes a ferromagnetic transition with both in-plane and out-of-plane magnetic components at Tc ≈ 100 K. Below T * = 50 K, the magnetic moments incline continuously toward the out-of-plane direction. At T = 1.5 K, where the spins are nearly aligned along the c axis, a spin reorientation occurs above a critical field Bc, giving rise to a spin component perpendicular to the plane defined by the field direction and the c axis. We suggest that both the temperature- and field-driven spin reorientations are associated with a change in the magnetocrystalline anisotropy, which is strongly coupled to the lattice degrees of freedom. This study elucidates the long-standing puzzles on the zero-field magnetic orders of Sr4Ru3O10 and provides new insights into the nature of the field-induced metamagnetic transition.
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Affiliation(s)
- M Zhu
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - P G Li
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana, 70118, USA
| | - Y Wang
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana, 70118, USA
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - W Tian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - H D Zhang
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - B D Phelan
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Z Q Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana, 70118, USA
| | - X Ke
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA.
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9
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Lampen-Kelley P, Banerjee A, Aczel AA, Cao HB, Stone MB, Bridges CA, Yan JQ, Nagler SE, Mandrus D. Destabilization of Magnetic Order in a Dilute Kitaev Spin Liquid Candidate. Phys Rev Lett 2017; 119:237203. [PMID: 29286699 DOI: 10.1103/physrevlett.119.237203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Indexed: 06/07/2023]
Abstract
The insulating honeycomb magnet α-RuCl_{3} exhibits fractionalized excitations that signal its proximity to a Kitaev quantum spin liquid state; however, at T=0, fragile long-range magnetic order arises from non-Kitaev terms in the Hamiltonian. Spin vacancies in the form of Ir^{3+} substituted for Ru are found to destabilize this long-range order. Neutron diffraction and bulk characterization of Ru_{1-x}Ir_{x}Cl_{3} show that the magnetic ordering temperature is suppressed with increasing x, and evidence of zizag magnetic order is absent for x>0.3. Inelastic neutron scattering demonstrates that the signature of fractionalized excitations is maintained over the full range of x investigated. The depleted lattice without magnetic order thus hosts a spin-liquid-like ground state that may indicate the relevance of Kitaev physics in the magnetically dilute limit of RuCl_{3}.
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Affiliation(s)
- P Lampen-Kelley
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Banerjee
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A A Aczel
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M B Stone
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C A Bridges
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J-Q Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S E Nagler
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D Mandrus
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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10
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Lee JH, Ma J, Hahn SE, Cao HB, Lee M, Hong T, Lee HJ, Yeom MS, Okamoto S, Zhou HD, Matsuda M, Fishman RS. Magnetic Frustration Driven by Itinerancy in Spinel CoV 2O 4. Sci Rep 2017; 7:17129. [PMID: 29215077 PMCID: PMC5719412 DOI: 10.1038/s41598-017-17160-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 11/13/2017] [Indexed: 11/12/2022] Open
Abstract
Localized spins and itinerant electrons rarely coexist in geometrically-frustrated spinel lattices. They exhibit a complex interplay between localized spins and itinerant electrons. In this paper, we study the origin of the unusual spin structure of the spinel CoV2O4, which stands at the crossover from insulating to itinerant behavior using the first principle calculation and neutron diffraction measurement. In contrast to the expected paramagnetism, localized spins supported by enhanced exchange couplings are frustrated by the effects of delocalized electrons. This frustration produces a non-collinear spin state even without orbital orderings and may be responsible for macroscopic spin-glass behavior. Competing phases can be uncovered by external perturbations such as pressure or magnetic field, which enhances the frustration.
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Affiliation(s)
- J H Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea.
| | - J Ma
- Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.,Key Laboratory of Artificial Structures and Quantum Control, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - S E Hahn
- Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA.,Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - M Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Tao Hong
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - H-J Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - M S Yeom
- Department of Applied Research and Network R&D, Center for Computational Science and Engineering, Division of National Supercomputing R&D, Korea Institute of Science and Technology Information (KISTI), 245 Daehak-ro, Daejeon, 34141, Republic of Korea.
| | - S Okamoto
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - H D Zhou
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - M Matsuda
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - R S Fishman
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
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11
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Liu JY, Hu J, Graf D, Zou T, Zhu M, Shi Y, Che S, Radmanesh SMA, Lau CN, Spinu L, Cao HB, Ke X, Mao ZQ. Unusual interlayer quantum transport behavior caused by the zeroth Landau level in YbMnBi 2. Nat Commun 2017; 8:646. [PMID: 28935862 PMCID: PMC5608808 DOI: 10.1038/s41467-017-00673-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 07/18/2017] [Indexed: 11/23/2022] Open
Abstract
Relativistic fermions in topological quantum materials are characterized by linear energy-momentum dispersion near band crossing points. Under magnetic fields, relativistic fermions acquire Berry phase of π in cyclotron motion, leading to a zeroth Landau level (LL) at the crossing point, a signature unique to relativistic fermions. Here we report the unusual interlayer quantum transport behavior resulting from the zeroth LL mode observed in the time reversal symmetry breaking type II Weyl semimetal YbMnBi2. The interlayer magnetoresistivity and Hall conductivity of this material are found to exhibit surprising angular dependences under high fields, which can be well fitted by a model, which considers the interlayer quantum tunneling transport of the zeroth LL's Weyl fermions. Our results shed light on the unusual role of zeroth LLl mode in transport.The transport behavior of the carriers residing in the lowest Landau level is hard to observe in most topological materials. Here, Liu et al. report a surprising angular dependence of the interlayer magnetoresistivity and Hall conductivity arising from the lowest Landau level under high magnetic field in type II Weyl semimetal YbMnBi2.
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Affiliation(s)
- J Y Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA
| | - J Hu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.
| | - D Graf
- National High Magnetic Field Lab, Tallahassee, FL, 32310, USA
| | - T Zou
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - M Zhu
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - Y Shi
- Department of Physics, University of California, Riverside, CA, 92521, USA
| | - S Che
- Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH, 43210, USA
| | - S M A Radmanesh
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, 70148, USA
| | - C N Lau
- Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH, 43210, USA
| | - L Spinu
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, 70148, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - X Ke
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
| | - Z Q Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.
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12
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Liu JY, Hu J, Zhang Q, Graf D, Cao HB, Radmanesh SMA, Adams DJ, Zhu YL, Cheng GF, Liu X, Phelan WA, Wei J, Jaime M, Balakirev F, Tennant DA, DiTusa JF, Chiorescu I, Spinu L, Mao ZQ. A magnetic topological semimetal Sr 1-yMn 1-zSb 2 (y, z < 0.1). Nat Mater 2017; 16:905-910. [PMID: 28740190 DOI: 10.1038/nmat4953] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
Weyl (WSMs) evolve from Dirac semimetals in the presence of broken time-reversal symmetry (TRS) or space-inversion symmetry. The WSM phases in TaAs-class materials and photonic crystals are due to the loss of space-inversion symmetry. For TRS-breaking WSMs, despite numerous theoretical and experimental efforts, few examples have been reported. In this Article, we report a new type of magnetic semimetal Sr1-yMn1-zSb2 (y, z < 0.1) with nearly massless relativistic fermion behaviour (m∗ = 0.04 - 0.05m0, where m0 is the free-electron mass). This material exhibits a ferromagnetic order for 304 K < T < 565 K, but a canted antiferromagnetic order with a ferromagnetic component for T < 304 K. The combination of relativistic fermion behaviour and ferromagnetism in Sr1-yMn1-zSb2 offers a rare opportunity to investigate the interplay between relativistic fermions and spontaneous TRS breaking.
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Affiliation(s)
- J Y Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - J Hu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - Q Zhang
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D Graf
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | - H B Cao
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S M A Radmanesh
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - D J Adams
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Y L Zhu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - G F Cheng
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
- Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - X Liu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - W A Phelan
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - J Wei
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
| | - M Jaime
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F Balakirev
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D A Tennant
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J F DiTusa
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - I Chiorescu
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - L Spinu
- Department of Physics and Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Z Q Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70018, USA
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13
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Zhao ZY, Wu Y, Cao HB, Zhou HD, Yan JQ. Three-dimensional magnetic interactions in quasi-two-dimensional PdAs 2O 6. J Phys Condens Matter 2017; 29:235801. [PMID: 28443827 DOI: 10.1088/1361-648x/aa6f9d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Millimeter-sized PdAs2O6 single crystals are grown using the vapor transport technique. The magnetic order at [Formula: see text] K is studied by measuring magnetic properties, specific heat, and neutron single crystal diffraction. The anisotropic magnetic susceptibility and a metamagnetic transition observed in magnetic fields above 20 kOe suggest that the magnetic moment lies in the ab plane, consistent with the magnetic structure determined by neutron single crystal diffraction. Below 140 K, Pd2+ ions order ferromagnetically in the ab plane but antiferromagnetically along the crystallographic c axis. The ordered moment is refined to be 2.09(2) [Formula: see text]/Pd2+ using the fitted magnetic form factor of Pd2+ . A weak λ-type anomaly around T N was observed in specific heat and the magnetic entropy change across T N is 1.72 J mol-1 K.This small entropy change and the temperature dependence of the magnetic susceptibility support the presence of short range correlations in a wide temperature range [Formula: see text] 250 K. The comparison with SrRu2O6 suggests that the magnetic interactions in PdAs2O6 are dominated by Pd-(O-[Formula: see text]-O)-Pd super-superexchange and three dimensional despite the quasi-two-dimensional arrangement of magnetic ions. The comparison with NiAs2O6 suggests that increasing covalency of isostructural compounds is an effective approach to design and to discover new materials with higher magnetic order temperatures in the localized regime.
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Affiliation(s)
- Z Y Zhao
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America. Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
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14
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Sinclair R, Cao HB, Garlea VO, Lee M, Choi ES, Dun ZL, Dong S, Dagotto E, Zhou HD. Canted magnetic ground state of quarter-doped manganites R 0.75Ca 0.25MnO 3 (R = Y, Tb, Dy, Ho, and Er). J Phys Condens Matter 2017; 29:065802. [PMID: 28002058 DOI: 10.1088/1361-648x/aa4de1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Polycrystalline samples of the quarter-doped manganites R 0.75Ca0.25MnO3 (R = Y, Tb, Dy, Ho, and Er) were studied by x-ray diffraction and AC/DC susceptibility measurements. All five samples are orthorhombic and exhibit similar magnetic properties: enhanced ferromagnetism below T 1 (∼80 K) and a spin glass (SG) state below T SG (∼30 K). With increasing R 3+ ionic size, both T 1 and T SG generally increase. The single crystal neutron diffraction results on Tb0.75Ca0.25MnO3 revealed that the SG state is mainly composed of a short-range ordered version of a novel canted (i.e. noncollinear) antiferromagnetic spin state. Furthermore, calculations based on the double exchange model for quarter-doped manganites reveal that this new magnetic phase provides a transition state between the ferromagnetic state and the theoretically predicted spin-orthogonal stripe phase.
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Affiliation(s)
- R Sinclair
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200, USA
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15
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Ziatdinov M, Banerjee A, Maksov A, Berlijn T, Zhou W, Cao HB, Yan JQ, Bridges CA, Mandrus DG, Nagler SE, Baddorf AP, Kalinin SV. Atomic-scale observation of structural and electronic orders in the layered compound α-RuCl 3. Nat Commun 2016; 7:13774. [PMID: 27941761 PMCID: PMC5159869 DOI: 10.1038/ncomms13774] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/01/2016] [Indexed: 01/24/2023] Open
Abstract
A pseudospin-1/2 Mott phase on a honeycomb lattice is proposed to host the celebrated two-dimensional Kitaev model which has an elusive quantum spin liquid ground state, and fascinating physics relevant to the development of future templates towards topological quantum bits. Here we report a comprehensive, atomically resolved real-space study by scanning transmission electron and scanning tunnelling microscopies on a novel layered material displaying Kitaev physics, α-RuCl3. Our local crystallography analysis reveals considerable variations in the geometry of the ligand sublattice in thin films of α-RuCl3 that opens a way to realization of a spatially inhomogeneous magnetic ground state at the nanometre length scale. Using scanning tunnelling techniques, we observe the electronic energy gap of ≈0.25 eV and intra-unit cell symmetry breaking of charge distribution in individual α-RuCl3 surface layer. The corresponding charge-ordered pattern has a fine structure associated with two different types of charge disproportionation at Cl-terminated surface.
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Affiliation(s)
- M Ziatdinov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Banerjee
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Maksov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Bredesen Center for Interdisciplinary Research, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - T Berlijn
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - W Zhou
- Material Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J-Q Yan
- Material Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Department of Material Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C A Bridges
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D G Mandrus
- Material Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Department of Material Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - S E Nagler
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Bredesen Center for Interdisciplinary Research, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - A P Baddorf
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.,Bredesen Center for Interdisciplinary Research, University of Tennessee, Knoxville, Tennessee 37996, USA
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16
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Kinoshita M, Seki S, Sato TJ, Nambu Y, Hong T, Matsuda M, Cao HB, Ishiwata S, Tokura Y. Magnetic Reversal of Electric Polarization with Fixed Chirality of Magnetic Structure in a Chiral-Lattice Helimagnet MnSb_{2}O_{6}. Phys Rev Lett 2016; 117:047201. [PMID: 27494497 DOI: 10.1103/physrevlett.117.047201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Indexed: 06/06/2023]
Abstract
The correlation between magnetic and dielectric properties has been investigated for the single crystal of the chiral triangular-lattice helimagnet MnSb_{2}O_{6}. We found that the spin-spiral plane in the ground state has a considerable tilting from the (110) plane and that the sign of the spin-spiral tilting angle is coupled to the clockwise or counterclockwise manner of spin rotation and accordingly to the sign of magnetically induced electric polarization. This leads to unique magnetoelectric responses such as the magnetic-field-induced selection of a single ferroelectric domain as well as the reversal of electric polarization just by a slight tilting of the magnetic field direction, where the chiral nature of the crystal structure plays a crucial role through the coupling of the chirality between the crystal and magnetic structures. Our results demonstrate that crystallographic chirality can be an abundant source of novel magnetoelectric functions with coupled internal degrees of freedom.
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Affiliation(s)
- M Kinoshita
- Department of Applied Physics and Quantum Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan
| | - S Seki
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- PRESTO, Japan Science and Technology Agency (JST), Tokyo 102-8666, Japan
| | - T J Sato
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - Y Nambu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - T Hong
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M Matsuda
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S Ishiwata
- Department of Applied Physics and Quantum Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan
- PRESTO, Japan Science and Technology Agency (JST), Tokyo 102-8666, Japan
| | - Y Tokura
- Department of Applied Physics and Quantum Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
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17
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Ma J, Kamiya Y, Hong T, Cao HB, Ehlers G, Tian W, Batista CD, Dun ZL, Zhou HD, Matsuda M. Static and Dynamical Properties of the Spin-1/2 Equilateral Triangular-Lattice Antiferromagnet Ba_{3}CoSb_{2}O_{9}. Phys Rev Lett 2016; 116:087201. [PMID: 26967439 DOI: 10.1103/physrevlett.116.087201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Indexed: 06/05/2023]
Abstract
We present single-crystal neutron scattering measurements of the spin-1/2 equilateral triangular-lattice antiferromagnet Ba_{3}CoSb_{2}O_{9}. Besides confirming that the Co^{2+} magnetic moments lie in the ab plane for zero magnetic field and then determining all the exchange parameters of the minimal quasi-2D spin Hamiltonian, we provide conclusive experimental evidence of magnon decay through observation of intrinsic line broadening. Through detailed comparisons with the linear and nonlinear spin-wave theories, we also point out that the large-S approximation, which is conventionally employed to predict magnon decay in noncollinear magnets, is inadequate to explain our experimental observation. Thus, our results call for a new theoretical framework for describing excitation spectra in low-dimensional frustrated magnets under strong quantum effects.
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Affiliation(s)
- J Ma
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Y Kamiya
- iTHES Research Group and Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Tao Hong
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G Ehlers
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - W Tian
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C D Batista
- Theoretical Division, T-4 and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Z L Dun
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - H D Zhou
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310-3706, USA
| | - M Matsuda
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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18
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Li CW, Hellman O, Ma J, May AF, Cao HB, Chen X, Christianson AD, Ehlers G, Singh DJ, Sales BC, Delaire O. Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics. Phys Rev Lett 2014; 112:175501. [PMID: 24836255 DOI: 10.1103/physrevlett.112.175501] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Indexed: 05/02/2023]
Abstract
The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe and PbTe are investigated with inelastic neutron scattering (INS) and first-principles calculations. The experiments show that, surprisingly, although SnTe is closer to the ferroelectric instability, phonon spectra in PbTe exhibit a more anharmonic character. This behavior is reproduced in first-principles calculations of the temperature-dependent phonon self-energy. Our simulations reveal how the nesting of phonon dispersions induces prominent features in the self-energy, which account for the measured INS spectra and their temperature dependence. We establish that the phase space for three-phonon scattering processes, combined with the proximity to the lattice instability, is the mechanism determining the complex spectrum of the transverse-optic ferroelectric mode.
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Affiliation(s)
- C W Li
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - O Hellman
- Department of Physics, Chemistry and Biology, Linköping University, Linköping SE-581 83, Sweden
| | - J Ma
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A F May
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - X Chen
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A D Christianson
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G Ehlers
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D J Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B C Sales
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - O Delaire
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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19
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Li HB, Cao HB, Li YP, Zhang Y, Liu HR. Effect of organic compounds on nitrite accumulation during the nitrification process for coking wastewater. Water Sci Technol 2010; 62:2096-2105. [PMID: 21045337 DOI: 10.2166/wst.2010.371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Coking wastewater is one of the most toxic industrial effluents since it contains high concentrations of ammonia and toxic organic compounds. Nitrification might be upset by the inhibitory effect of organic compounds during the biological treatment of the wastewater. In this study, shortcut nitrification was obtained in a sequencing batch bioreactor (SBR) and the inhibitory effect of organic compounds on the nitrification was examined when temperature was 30±1°C, pH was 7.0-8.5, and dissolved oxygen concentration was 2.0-3.0 mg L(-1). The inhibitory effect of organic compounds was presumed to be one of the main factors to obtain satisfactory nitrite accumulation. The effect of organic compounds on nitrification was examined in the SBR with initial inhibitor concentrations ranging from 0 to 80 mg L(-1), including phenol, pyrocatechol, resorcin, benzene, quinoline, pyridine and indole. The inhibitory effect became stronger with the increase in the concentration, and it was presumed to take place through a direct mechanism resulting from biological toxicity of the inhibitor itself. Furthermore, the inhibitory effect on ammonia oxidation was slighter than that on nitrite oxidation, and the nitrite accumulation ratio during the nitrification was determined by the difference between the reaction rates of above two processes.
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Affiliation(s)
- H B Li
- Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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20
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Abstract
The local Yb(3+) magnetic susceptibility tensor was recently measured in the frustrated pyrochlore compound Yb(2)Ti(2)O(7) by means of in-field polarized neutron scattering in a single crystal. A very anisotropic effective exchange tensor was derived for the Yb(3+) ion. Using this result, we reinterpret here the data for the powder susceptibility in Yb(2)Ti(2)O(7). We show that, in the case of a well-isolated Kramers doublet with anisotropic g and exchange tensors, the inverse susceptibility for a powder sample does not strictly obey a Curie-Weiss law at low temperature. We discuss the consequences regarding the paramagnetic Curie temperature, usually taken as a measure of the exchange/dipolar interaction, and the exotic 'slow fluctuation' ground state of Yb(2)Ti(2)O(7).
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Affiliation(s)
- H B Cao
- CEA, Centre de Saclay, Laboratoire Léon Brillouin, F-91191 Gif-sur-Yvette, France
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21
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Pan XR, Li GW, Hu YH, Wang JX, Yang WY, An ZX, Hu ZX, Lin J, Xiao JZ, Cao HB, Liu PA, Jiang XG, Jiang YY, Wang JP, Zheng H, Zhang H, Bennett PH, Howard BV. Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The Da Qing IGT and Diabetes Study. Diabetes Care 1997; 20:537-44. [PMID: 9096977 DOI: 10.2337/diacare.20.4.537] [Citation(s) in RCA: 2511] [Impact Index Per Article: 93.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Individuals with impaired glucose tolerance (IGT) have a high risk of developing NIDDM. The purpose of this study was to determine whether diet and exercise interventions in those with IGT may delay the development of NIDDM, i.e., reduce the incidence of NIDDM, and thereby reduce the overall incidence of diabetic complications, such as cardiovascular, renal, and retinal disease, and the excess mortality attributable to these complications. RESEARCH DESIGN AND METHODS In 1986, 110,660 men and women from 33 health care clinics in the city of Da Qing, China, were screened for IGT and NIDDM. Of these individuals, 577 were classified (using World Health Organization criteria) as having IGT. Subjects were randomized by clinic into a clinical trial, either to a control group or to one of three active treatment groups: diet only, exercise only, or diet plus exercise. Follow-up evaluation examinations were conducted at 2-year intervals over a 6-year period to identify subjects who developed NIDDM. Cox's proportional hazard analysis was used to determine if the incidence of NIDDM varied by treatment assignment. RESULTS The cumulative incidence of diabetes at 6 years was 67.7% (95% CI, 59.8-75.2) in the control group compared with 43.8% (95% CI, 35.5-52.3) in the diet group, 41.1% (95% CI, 33.4-49.4) in the exercise group, and 46.0% (95% CI, 37.3-54.7) in the diet-plus-exercise group (P < 0.05). When analyzed by clinic, each of the active intervention groups differed significantly from the control clinics (P < 0.05). The relative decrease in rate of development of diabetes in the active treatment groups was similar when subjects were stratified as lean or overweight (BMI < or > or = 25 kg/m2). In a proportional hazards analysis adjusted for differences in baseline BMI and fasting glucose, the diet, exercise, and diet-plus-exercise interventions were associated with 31% (P < 0.03), 46% (P < 0.0005), and 42% (P < 0.005) reductions in risk of developing diabetes, respectively. CONCLUSIONS Diet and/or exercise interventions led to a significant decrease in the incidence of diabetes over a 6-year period among those with IGT.
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Affiliation(s)
- X R Pan
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing, China
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Yang WY, Cao HB, Pan XR. [Effects of sex hormones on plasma lipoproteins in middle older age non-diabetes, diabetes and coronary heart disease]. Zhonghua Nei Ke Za Zhi 1993; 32:552-5. [PMID: 8269788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We has observed the effects of sex hormones on plasma lipoproteins by analysing 165 patients of non-diabetes mellitus (NDM), diabetes mellitus (DM) and coronary heart disease (CHD) in the elder than 45 years. Of these subjects, NDM were 54, DM 47, CHD 48 and DM with CHD 16. The result statistically showed that is a significant difference in high density lipoprotein cholesterol (HDL-C) and Apolipoprotein A1 (Apo-A1) between male and female subjects in NDM group and general population (P = 0.0001, 0.003 and P = 0.009, 0.002 respectively), but this statistically significant difference could not be observed between male and female patients in groups of DM, CHD and DM with CHD. After adjusting multiple factors of age, body mass index (BMI), estradiol (E2), fasting plasma insulin (FINS), fasting blood glucose (FBS) by the stepwise procedure analysis, the levels of HDL-C and Apo-A1 have significantly negative association with the level of testosterone (T) (P = 0.0012 and 0.0040), however, have no association with E2. Total cholesterol (TC) and triglyceride (TG) have no association with T and E2. The result suggests that T should be an independent risk factor which reduces HDL-C level.
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Affiliation(s)
- W Y Yang
- China-Japan Friendship Hospital, Beijing
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Yang WY, Han R, Cao HB. [Delayed gastric emptying in diabetes mellitus]. Zhonghua Nei Ke Za Zhi 1991; 30:399-401, 454-5. [PMID: 1752150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Function of gastric motility was studied in thirty one diabetes mellitus patients by testing gastric emptying time (GET). The test was performed by giving patients food labelled with 99mTc. The results showed that GET in patients with diabetes mellitus was significantly delayed as compared with that in the controls (P less than 0.001). 15 among the 31 diabetic patients had delayed GET, accounting for 48.4%. There was no difference in age, duration of the disease, treatment regimen and microvascular complications between patients with delayed GET and those with normal GET. The only difference was the obviously increased incidence of autonomic nerve dysfunction in the former group of patients (P less than 0.05). We concluded that the incidence of delayed gastric emptying time was higher in diabetic patients with autonomic neuropathy.
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Affiliation(s)
- W Y Yang
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing
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