​Rare-earth (RE) based geometrically frustrated magnets represent a novel approach in the search for enigmatic quantum spin liquids (QSLs). Dr Andrej Zorko has been coming to ISIS to run experiments for 15 years. His team's latest research​, published in Nature Materials, identified a novel family of RE heptatantalates RETa7O19, where in the Nd case strong Ising anisotropy on the triangular lattice leads to a QSL state. The nature of the RE will have a strong influence on the magnetic anisotropy, which primarily determines the ground state on frustrated lattices.

The team returned to ISIS to study ErTa7O19 with the same crystal structure but twice as strong magnetic interactions. Their bulk magnetic characterizations did not show any signature of magnetic ordering, which called for more sensitive local-probe investigations that could unambiguously confirm and characterize the expected QSL state.

“We are working on quantum materials and are interested in their magnetic properties for use in future technologies," explained Dr Zorko. “Such materials do not magnetically order themselves but they can transition into more complex magnetic states, like quantum spin liquids. Our investigations use different experimental techniques that complement each other. Here at ISIS, we can access techniques that are unique and highly sensitive, combining complementary insights using muon spectroscopy and neutron scattering via MUSR. There are only a few places in the world where external researchers can use both these techniques. My experimental team has broad expertise in both, enabling us to run experiments on different instruments in parallel."