Complex Dirac-like Electronic Structure in Atomic Site Ordered Rh<sub>3</sub>In<sub>3.4</sub>Ge<sub>3.6</sub>

ORAL

Abstract

We report the synthesis via an indium flux method of a novel single-crystalline compound Rh3In3.4Ge3.6 that belongs to the cubic Ir3Ge7 structure type. In Rh3In3.4Ge3.6, the In and Ge atoms choose to preferentially occupy, respectively, the 12d and 16f sites of the Im-3m space group, thus creating a colored version of the Ir3Ge7 structure. Like the other compounds of the Ir3Ge7 family, Rh3In3.4Ge3.6 shows potential as a thermoelectric displaying a relatively large power factor, PF ~ 2 mW/cmK2, at a temperature T ~ 225 K albeit showing a modest figure of merit, ZT = 8x10-4, due to the lack of a finite band gap. Remarkably, band structure calculations reveal that this compound displays a complex Dirac-like electronic structure relatively close to the Fermi level. The electronic structure is composed of several Dirac type-I and type-II nodes, and even Dirac type-III nodes that result from the crossing between a flat band having nearly zero group velocity and a linearly dispersing band.

*L.B. and A.F.S. acknowledges supported from DOE-BES. The National High Magnetic Field Laboratory acknowledges support from US NSF Cooperative Agreement Grant No. DMR-1644779 and the state of Florida.

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Presenters

  • Aikaterini Flessa Savvidou

    • National High Magnetic Field Laboratory

Authors

  • Aikaterini Flessa Savvidou

    • National High Magnetic Field Laboratory

  • Judith K. Clark

    • Department of Chemistry & Biochemistry, Florida State University

  • Hua Wang

    • Texas A&M University
    • Department of Materials Science and Engineering, Texas A&M University

  • Kaya Wei

    • National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory, Florida State University
    • CMS, National High Magnetic Laboratory
    • Florida State University

  • Eun Sang Choi

    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory and Department of Physics, Florida State University
    • National High Magnetic Field Lab
    • Physics, Florida State University
    • National High Field Magnet Laboratory
    • Florida Sate University

  • Shirin Mozaffari

    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory

  • Xiaofeng Qian

    • Texas A&M University
    • Department of Materials Science and Engineering, Texas A&M University

  • Michael Shatruk

    • Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
    • Florida State University
    • Department of Chemistry & Biochemistry, Florida State University

  • Luis Balicas

    • National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Lab
    • Condensed Matter Science, National High Magnetic Field Laboratory