Avoided ferromagnetic quantum critical point in pressurized La<sub>5</sub>Co<sub>2</sub>Ge<sub>3</sub>

ORAL

Abstract

A quantum phase transition is a phase transition that occurs at 0 K. For many second-order phase transitions, application of a magnetic field, doping or pressure can suppress the transition temperature and lead to a quantum critical point (QCP). However, avoided quantum criticality is often observed in intermetallic, ferromagnetic systems. The mechanism behind this phenomenon has been discussed intensively in recent years. Lately, we discovered a new ferromagnetic compound, La5Co2Ge3, which has a Curie temperature Tc ~ 3.8 K. The physical properties under pressure and the pressure dependence of Tc are studied up to ~ 5 GPa. We find that a ferromagnetic QCP is avoided by the appearance of a new, most likely magnetic, phase. Details of the T-p phase diagram and the possible nature of the new phase will be discussed.

*This work was carried out at Iowa State University and supported by Ames Laboratory, US DOE, under Contract No. DE-AC02- 07CH11358, by the Gordon and Betty Moore Foundation's EPiQS Initiative and the W. M. Keck Foundation.

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Presenters

  • Li Xiang

    • Ames Laboratory and Iowa State University
    • Iowa State University, Ames Laboratory
    • Iowa State University

Authors

  • Li Xiang

    • Ames Laboratory and Iowa State University
    • Iowa State University, Ames Laboratory
    • Iowa State University

  • Scott Saunders

    • Iowa State University

  • Sergey L. Bud'ko

    • Iowa State University
    • Ames Laboratory and Iowa State University
    • Ames Lab
    • Ames laboratory, Ames, IA
    • Department of Physics & Astronomy, Iowa State University/Ames Laboratory
    • Ames Laboratory
    • Department of Physics and Astronomy, Iowa State University/Ames Laboratory
    • Iowa State University and Ames Laboratory
    • Iowa State University, Ames Laboratory
    • Division of Materials Sciences & Engineering, Ames Lab and Iowa State University
    • Iowa State University/Ames Laboratory

  • Paul C Canfield

    • Iowa State University
    • Ames Laboratory and Iowa State University
    • Ames Lab
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
    • Ames laboratory, Ames, IA
    • Ames Laboratory, Iowa State University
    • Department of Physics & Astronomy, Iowa State University/Ames Laboratory
    • Department of Physics and Astronomy, Iowa State University/Ames Laboratory
    • Iowa State University and Ames Laboratory
    • Iowa State University, Ames Laboratory
    • Department of Physics and Astronomy, Iowa State University
    • Division of Materials Sciences & Engineering, Ames Lab and Iowa State University
    • Department of Physics and Astronomy, Ames Laboratory/Iowa State Univeristy
    • Iowa State University/Ames Laboratory