Abstract
Inelastic neutron scattering (INS) in variable magnetic field and high-field magnetization
measurements in the millikelvin temperature range were performed to gain insight into the
low-energy magnetic excitation spectrum and the field-induced level crossings in the molecular
spin cluster {Cr8}-cubane. These complementary techniques provide consistent estimates of the
lowest level-crossing field. The overall features of the experimental data are explained using an
isotropic Heisenberg model, based on three distinct exchange interactions linking the eight CrIII
paramagnetic centers (spins s = 3/2), that is supplemented with a relatively large molecular
magnetic anisotropy term for the lowest S = 1 multiplet. It is noted that the existence of the
anisotropy is clearly evident from the magnetic field dependence of the excitations in the INS
measurements, while the magnetization measurements are not sensitive to its effects.
