Neutron scattering in dimers

Insulating compounds containing dimers of transition metal and rare earth ions have been studied by inelastic neutron scattering (INS). Energy splittings can be directly determined, and the corresponding parameters are easily extracted from the experimental data. The intensities of dimer excitations are modulated by an interference term reflecting the distance between the magnetic ions within the dimers. The INS technique is particularly powerful for the study of effects like: temperature dependence of exchange, the role of biquadratic exchange, the combination of crystal-field and exchange interactions in rare earth dimers, competing intra and interdimer exchange in a new family of singlet-ground state magnets: Cs3Cr2X9(X=Cl,Br,I)