IrTe$_2$ presents a layered compound with a triangular lattice. It is known to exhibit a first order structural phase transition at approximately 260~K which is of a first order, corresponding to a formation of a superstructure with a period of five unit cells. Using polarized Raman spectroscopy we have studied the temperature dependence of 14 observed Raman allowed phononic modes. These phonons couple strongly to this transition and one additional first order transition at approximately 170~K. In the high-temperature phase only 3 modes are observed, while below approximately 280~K all 14 modes become visible. Below approximately 170~K only 11 modes are observed. Our results shed light on the possible mechanism driving the transitions.
*ACL, VKT and GB acknowledge support by NSF DMR-1104884.
–
Authors
Alexander Lee
Rutgers, The State University of New Jersey
Verner Thorsmolle
Rutgers, the State University of New Jersey
Rutgers, The State University of New Jersey
Sergey Artyukhin
Rutgers, The State University of New Jersey
J.J. Yang
Pohang University of Science and Technology, Korea
Pohang University of Science and Technology
Laboratory for Pohang Emergent Materials and Department of Physics, Pohang University
S.-W. Cheong
Rutgers University
Department of Physics, Rutgers University
Rutgers University, NJ, USA
Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers U., NJ, USA
Rutgers, The State University of New Jersey
Department of Physics and Astronomy, Rutgers University
Rutgers Center for Emergent Materials and Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway 08854, NJ, USA
