Ground state of the geometrically frustrated compound Tb₂Sn₂O₇

Abstract

Despite the observation of magnetic neutron reflections at low temperatures, muon-spin experiments have suggested the ground state of the geometrically frustrated magnetic material Tb₂Sn₂O₇ to be dynamical. This unique situation requires additional characterizations of this magnetic ground state. Here we report a neutron spin-echo investigation which supports the existence of a dynamical component in the ground state. This result is backed by a thorough analysis of the diffraction profiles. A physical model is put forward in which the energy splitting between the ground and first excited states of the Tb³⁺ ion is comparable to other energies present in this frustrated system.