Neutron spectroscopic study of anisotropic exchange in the dimer compound Cs3Ho2Br9

Abstract
The inelastic-neutron-scattering technique was used to measure magnetic excitations of Ho3+ dimers in Cs3 Ho2 Br9. The usual phenomenological models failed to reproduce the observed energy spectra. An exchange-tensor formalism, on the other hand, which treats the Ho3+ ground state as an effective S=2 state, provides an excellent description of the observed energy splittings and intensities.