Pressure-evolution of a symmetry-broken <i>S</i> = ½ dimer magnet

ORAL

Abstract

A lattice of weakly interacting, antiferromagnetically coupled spin-half dimers can be well described within a Bose-Einstein condensate (BEC) of magnons model, provided the rotational symmetry of the spin Hamiltonian is preserved. The material CuVOF4(H2O)6H2O, appears to exhibit behaviour typical of a dimer system, with electron-spin resonance and magnetometry data confirming the field-induced closing of an energy-gap between the excited triplet-state and singlet ground-state energy levels. However, as the dimer-unit is composed of two unlike spin-half ions, Cu(II) and V(IV), we are presented with the interesting situation where the rotational symmetry of the system is broken by the spins in the dimer-units themselves. Here we discuss the unusual hydrogen-bond-mediated exchange pathways in this material and the resultant phase diagram. In addition, we show that the application of hydrostatic pressure serves to tune the magnitude of the intradimer exchange interaction, as well as push the system through a structural phase-transition at pressures beyond 20 kbar.

**This project has received funding from the European Research Council (grant no. 681260).
*Work at EWU was supported by NSF Grant No. DMR-1703003.

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Presenters

  • Sam Curley

    • Department of Physics, University of Warwick

Authors

  • Sam Curley

    • Department of Physics, University of Warwick

  • Matthew J Coak

    • Department of Physics, University of Warwick
    • University of Warwick
    • Univ of Warwick

  • Robert C Williams

    • Department of Physics, University of Warwick

  • Saman Ghannadzadeh

    • Department of Physics, University of Oxford

  • Dmytro Kamenskyi

    • University of Augsburg

  • Andreas Schneider

    • University of Augsburg

  • Susumo Okubo

    • Kobe University

  • Takahiro Sakurai

    • Kobe University

  • Hitoshi Ohta

    • Kobe University

  • Benjamin Michael Huddart

    • Department of Physics, Durham University
    • Department of Physics, University of Durham

  • Tom Lancaster

    • Department of Physics, Durham University
    • Department of Physics, University of Durham

  • David E Graf

    • National High Magnetic Field Laboratory
    • Florida State University
    • National High Magnetic Field Lab, Florida State University
    • National High Magnetic Field Laboratory, Tallahassee and Florida State University
    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory (FSU)
    • Department of Physics, Florida State University
    • National High Magnetic Field Laboratory and Department of Physics, Florida State University
    • National High Magnetic Field Lab
    • National High Magnetic Field Laboratory, Tallahassee, FL
    • CMS, National High Magnetic Laboratory

  • Jere Tidy

    • Department of Chemistry, University of Warwick

  • Mark Senn

    • Department of Chemistry, University of Warwick
    • Chemistry, University of Warwick

  • Jamie L Manson

    • Department of Chemistry and Biochemistry, Eastern Washington University
    • Eastern Washington University

  • Paul Goddard

    • Department of Physics, University of Warwick
    • University of Warwick
    • Physics, University of Warwick