Muon spectroscopy to probe spin dynamics in hexagonal Ba3Tb(BO3)3

We reported structural and magnetic data on a new low-temperature phase of Ba3Tb(BO3)3 in 2020. The material has a layered triangular lattice arrangement of magnetic terbium ions and therefore displays geometric frustration. No long-range magnetic ordering has been observed down to temperatures around 75 millikelvin using powder neutron diffraction. We also observe an absence of diffuse scattering, which may imply that the terbium spins remain dynamic down to very low temperatures - an experimental signature of a quantum spin liquid. Muon spectroscopy at ISIS is proposed as a way to investigate the spin dynamics of this material at a range of temperatures. We request 1 day of beamtime using a standard cryostat, and a further 1 day using a dilution fridge if the first measurement indicates that lower temperature data would be useful.