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.
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.
*This project has received funding from the European Research Council (grant no. 681260). We also thank the EPSRC.
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Presenters
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Matthew Pearce
- Physics, Warwick University
- Physics, University of Warwick
- University of Warwick
- Department of Physics, University of Warwick
- Physics Department, University of Warwick, Coventry, CV4 7AL, United Kingdom