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Magnetometry and transport studies of single-crystal pyrochlore iridates

ORAL

Abstract

Magnetic pyrochlore oxides have attracted significant interest due to their geometrically frustrated lattice, which acts to suppress long range magnetic order and leads to a variety of unusual magnetic ground states and exotic excitations.

Some of the most studied pyrochlores are the spin ices Ho2Ti2O7 and Dy2Ti2O7 – here the rare earth ions are ferromagnetic whilst the Ti is nonmagnetic. Recently, the pyrochlore iridates (R2Ir2O7, R = rare earth) have risen to prominence. Here, both the rare earth and the Ir are magnetic; the added complexity afforded by the Ir magnetism may be expected to yield a rich variety of physical phenomena. For instance, most of the pyrochlore iridates exhibit a metal to insulator transition which accompanies the ordering of the Ir into an ‘all-in-all-out’ configuration.

Here we report on magnetisation and resistivity measurements on new single crystals of pyrochlore iridates. We present a systematic study of the evolution of these properties with magnetic field, temperature and angle. Supported by Monte Carlo simulations we present our interpretation of the highly anisotropic and hysteretic behaviour observed as well as its wider significance.

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Presenters

  • Matthew Pearce

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

Authors

  • Matthew Pearce

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

  • Kathrin Goetze

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

  • Attila Szabo

    TCM, University of Cambridge, University of Cambridge

  • Tycho Sikkenk

    Physics, Utrecht University, University of Utrecht

  • Martin Lees

    Physics, University of Warwick, University of Warwick, Department of Physics, The University of Warwick, Coventry, CV4 7AL, United Kingdom

  • Andrew Boothroyd

    Physics, University of Oxford

  • Dharmalingam Prabhakaran

    Physics, University of Oxford, Clarendon Laboratory, Department of Physics, University of Oxford

  • Claudio Castelnovo

    Univ of Cambridge, TCM, University of Cambridge, University of Cambridge, T.C.M. Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom

  • Paul Goddard

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