Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                

Coupled magnetic and structural phase transitions in the antiferromagnetic polar metal Pb2CoOsO6 under pressure

Yuanyuan Jiao, Yue-Wen Fang, Jianping Sun, Pengfei Shan, Zhenhai Yu, Hai L. Feng, Bosen Wang, Hanming Ma, Yoshiya Uwatoko, Kazunari Yamaura, Yanfeng Guo, Hanghui Chen, and Jinguang Cheng
Phys. Rev. B 102, 144418 – Published 13 October 2020
PDFHTMLExport Citation
Abstract
Authors
Article Text
  • INTRODUCTION
  • EXPERIMENTAL AND COMPUTATIONAL DETAILS
  • RESULTS AND DISCUSSION
  • CONCLUSION
  • ACKNOWLEDGMENTS
  • APPENDICES
    • References

    Abstract

    Pb2CoOsO6 is a newly synthesized polar metal in which inversion symmetry is broken by the magnetic frustration in an antiferromagnetic ordering of Co and Os sublattices. The coupled magnetic and structural transition occurs at 45 K at ambient pressure. Here, we perform transport measurements and first-principles calculations to study the pressure effects on the magnetic/structural coupled transition of Pb2CoOsO6. Experimentally, we monitor the resistivity anomaly at TN under various pressures up to 11 GPa in a cubic anvil cell apparatus. We find that TN determined from the resistivity anomaly first increases quickly with pressure in a large slope of dTN/dP=+6.8(8)K/GPa for P<4GPa and, then, increases with a much reduced slope of 1.8(4) K/GPa above 4 GPa. Our first-principles calculations suggest that the observed discontinuity of dTN/dP around 4 GPa may be attributed to the vanishing of the Os magnetic moment under pressure. Pressure substantially reduces the Os moment and completely suppresses it above a critical value, which relieves the magnetic frustration in the antiferromagnetic ordering of Pb2CoOsO6. The Co and Os polar distortions decrease with the increasing pressure and simultaneously vanish at the critical pressure. Therefore, above the critical pressure, a new centrosymmetric antiferromagnetic state emerges in Pb2CoOsO6, distinct from the one under ambient pressure, thus, showing a discontinuity in dTN/dP.

    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Received 20 July 2020
    • Accepted 21 September 2020

    DOI:https://doi.org/10.1103/PhysRevB.102.144418

    ©2020 American Physical Society

    Physics Subject Headings (PhySH)

    1. Research Areas
    AntiferromagnetismDensity of statesElectronic structureMagnetic phase transitionsMagnetoelectric effectTransport phenomena
    1. Physical Systems
    MultiferroicsNoncentrosymmetric materialsTransition metal oxides
    1. Techniques
    Density functional calculationsPressure techniquesResistivity measurements
    Condensed Matter, Materials & Applied Physics

    Authors & Affiliations

    Yuanyuan Jiao1,2,*,†, Yue-Wen Fang3,4,*, Jianping Sun1,2, Pengfei Shan1,2, Zhenhai Yu5, Hai L. Feng1, Bosen Wang1,2,6, Hanming Ma7, Yoshiya Uwatoko7, Kazunari Yamaura8,9, Yanfeng Guo5,‡, Hanghui Chen4,10,§, and Jinguang Cheng1,2,6,∥

    • 1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
    • 2School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
    • 3Laboratory for Materials and Structures & Tokyo Tech World Research Hub Initiative (WRHI), Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
    • 4NYU-ECNU Institute of Physics, New York University Shanghai, Shanghai, 200062, China
    • 5School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
    • 6Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
    • 7Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
    • 8International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba 305-0044, Japan
    • 9Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo 060-0810, Japan
    • 10Department of Physics, New York University, New York 10012, USA

    • *These two authors contributed equally to this work.
    • †Present address: Faculty of Science, Wuhan University of Science and Technology, Wuhan, Hubei 430065, China.
    • ‡guoyf@shanghaitech.edu.cn
    • §hanghui.chen@nyu.edu
    • ∥jgcheng@iphy.ac.cn

    Article Text (Subscription Required)

    Click to Expand

    References (Subscription Required)

    Click to Expand
    Issue

    Vol. 102, Iss. 14 — 1 October 2020

    Reuse & Permissions
    Access Options
    Author publication services for translation and copyediting assistance advertisement

    Authorization Required

    Log In
    Other Options
    ×

    Images

    • Figure 1
      Figure 1

      Temperature dependences of (a) magnetic susceptibility χ(T) and its inverse χ−1(T), and (b) resistivity ρ(T) and its derivative dρ/dT for the Pb2CoOsO6 single crystal. The antiferromagnetic transition at TN=43K is marked by a vertical broken line.

      Reuse & Permissions
    • Figure 2
      Figure 2

      Temperature dependences of (a) resistivity ρ(T) and (b) its second derivative d2ρ/dT2 under various pressures up to 11 GPa for the Pb2CoOsO6 single crystal. (c) A plot of δρ≡(ρ−ρ0) versus T2 for the ρ(T) data at low temperatures. The solid lines are linear fitting curves to extract the quadratic-T coefficient A.

      Reuse & Permissions
    • Figure 3
      Figure 3

      Pressure dependence of (a) the antiferromagnetic transition temperature TN and (b) the quadratic-T coefficient A of the Pb2CoOsO6 single crystal.

      Reuse & Permissions
    • Figure 4
      Figure 4

      The total density of states (DOS) of Pb2CoOsO6 under 0, 1, 3, 5, 7, and 9 GPa, obtained from (a) spin-polarized DFT calculations and (b) DFT+SOC calculations. Note that in panel (a), the spin up and spin down are identical due to the antiferromagnetic ordering, thus, they are summed in the DOS. The dashed line is the Fermi level.

      Reuse & Permissions
    • Figure 5
      Figure 5

      Magnetic moments of (a) Co and (b) Os in Pb2CoOsO6 under 0–9GPa. The magnetic moments are obtained using DFT and DFT+SOC calculations on the fully optimized crystal structures. The lines are used to guide the eye.

      Reuse & Permissions
    • Figure 6
      Figure 6

      (a) The optimized crystal structure of Pb2CoOsO6 in an 80-atom cell and a metal-oxygen BO6 octahedron (B=Co or Os). The polar displacement for the B-site metal ion is defined as δ=14∑i=14di where di=zB–zOi and the index i runs over 1–4 because there are four in-plane oxygen atoms in a BO6 octahedron. In panel (a), only d1 and d2 are shown for clarity using the black double-headed arrows. (b) The average Co-O and Os-O polar displacements δ in Pb2CoOsO6 under 0–9GPa. The lines in panel (b) are used to guide the eye.

      Reuse & Permissions
    ×

    Sign up to receive regular email alerts from Physical Review B

    Log In

    Cancel
    ×

    Search

    Article Lookup

    Paste a citation or DOI
    Enter a citation
    ×