High pressure X-ray study of the lattice dimerization in the S$=$1/2 chain quantum magnet TiOCl.

ORAL

Abstract

TiOCl, composed of S$=$1/2 chains of Ti ions, is a good realization of a spin-Peierls system. Considerable effort has been put into doping the material with the goal of achieving metallization. Interestingly, high pressure resistivity shows a dramatic decrease of its insulating behavior, which may coincide with the emergence of charge density wave order. Therefore, high pressure of the structure with x-rays are important in further exploring the phase diagram. Upon cooling under normal pressure conditions, TiOCl exhibits a transition to an incommensurate nearly dimerized state at Tc2 $=$ 92 K and to a commensurate dimerized state at Tc1 $=$ 66 K. Here we map its complex temperature vs. pressure phase diagram with x-rays on a single crystal in a high pressure diamond anvil down to 6 K in temperature and to pressures up to approximately 14.5 GPa.

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Authors

  • Costel Rotundu

    • SIMES, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
    • Stanford University and SLAC National Accelerator Laboratory

  • Jiajia Wen

    • Department of Applied Physics, Stanford University, Stanford, CA 94305, USA

  • Wei He

    • Department of Applied Physics, Stanford University, Stanford, CA 94305, USA

  • Yejun Feng

    • The Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA

  • Yongseong Choi

    • The Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA

  • Daniel Haskel

    • The Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA

  • Young S. Lee

    • Department of Applied Physics, Stanford University, Stanford, CA 94305, USA and SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA