<i>In-situ</i> Electron Microcopy Observation of Phase Transitions in Bulk IrTe<sub>2</sub>

ORAL

Abstract

Transition-metal dichalcogenide IrTe2 has attracted extensive attention because of its intriguing structural transitions, abnormal resistivity, and superconductivity. While it forms a trigonal phase at room temperature, the structure below the phase transition at 280 K is is still in debate. With in-situ transmission and scanning transmission electron microscopy (STEM), we study the phase transitions of IrTe2 single crystal from room temperature down to 20 K. The electron diffraction and imaging results show that IrTe2 below 280 K is phase separated, with the coexistence of the well-characterized 5 × 1 × 5 phase, an intergrowth phases with multiple modulated vectors, and the remaining trigonal phase. The 5 × 1 × 5 phase is present down to 20 K, but we never observe the 6 × 1 × 6 or 8 × 1 × 8 phase previously reported. The valence states of IrTe2 for different phases have been investigated by electron energy loss spectroscopy. A clear picture of the temperature-dependent structural evolution of bulk IrTe2, which is essential to understand the unique electric and magnetic behaviors, will be presented.

**Supported by U.S. NSF through grant No. NSF DMR-1504226

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Presenters

  • Zhen Wang

    • Department of Physics and Astronomy, Baton Rouge, Louisiana 70803, US, Louisiana State University
    • Louisiana State University

Authors

  • Zhen Wang

    • Department of Physics and Astronomy, Baton Rouge, Louisiana 70803, US, Louisiana State University
    • Louisiana State University

  • Guixin Cao

    • Ohio State University
    • Louisiana State University

  • Zhenyu Zhang

    • University of Science and Technology of China
    • ICQD, University of Science and Technology of China
    • Louisiana State University

  • Myung-Geun Han

    • Condensed Matter Physics and Materials Science, Brookhaven National Lab
    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • 2Condensed Matter Physics and Materials Science Departement, Brookhaven National Laboratory

  • Lijun Wu

    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • CMPMSD, Brookhaven National Laboratory
    • 2Condensed Matter Physics and Materials Science Departement, Brookhaven National Laboratory

  • Yimei Zhu

    • Department of Energy Science and Technology, Upton, New York 11973, USA, Brookehaven National Laboratory
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory
    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • CMPMSD, Brookhaven National Laboratory
    • 2Condensed Matter Physics and Materials Science Departement, Brookhaven National Laboratory

  • Rongying Jin

    • Louisiana State University
    • Physics, Louisiana State University
    • Physics and astronomy, Louisiana State University
    • 2Condensed Matter Physics and Materials Science Departement, Brookhaven National Laboratory
    • Department of Physics and Astronomy, Louisiana State University
    • Physics and Astronomy, Louisiana State University

  • E Ward Plummer

    • Louisiana State University
    • Department of Physics & Astronomy, Louisiana State University
    • Dept. of Physics and Astronomy, Louisiana State University, USA
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge
    • Physics and astronomy, Louisiana State University