Abstract
Rare-earth garnets are an exciting playground for studying the exotic magnetic properties of the frustrated hyperkagome lattice. Here we present a comprehensive study of the single ion and collective magnetic properties of the garnet . Using inelastic neutron scattering, we find a crystal-field ground-state doublet for with strong Ising anisotropy along local [100] axes. Magnetic susceptibility and heat-capacity measurements provide evidence for long-range magnetic ordering with , and no evidence for residual entropy is found when cooling through the ordering transition. Neutron powder diffraction reveals that the ground-state spin configuration corresponds to the six-sublattice, Ising antiferromagnetic state () common to many of the rare-earth garnets. However, we also found that appears to be insensitive to the ordering transition in this material, in which a low-temperature relaxation plateau was observed with no evidence of spontaneous muon precession. The combined muon and neutron results may be indicative of a dynamical ground state with a relatively long correlation time. Despite this potential complication, our work indicates that is an excellent model system for studying the complex metamagnetism expected for a multiaxis antiferromagnet.
1 More- Received 9 May 2019
DOI:https://doi.org/10.1103/PhysRevB.100.184415
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