Magnetic excitation in a new spin gap compound   Cu$_2$Sc$_2$Ge$_4$O$_{13}$: Comparison to Cu$_2$Fe$_2$Ge$_4$O$_{13}$
  The compound \CuScGeO is presented as a new member of the family of weakly coupled spin chain and dimer compounds \CuMGeO. Magnetic susceptibility, heat capacity, and neutron inelastic scattering measurements reveal that the compound has the same spin dimer component as \CuFeGeO. The observed narrow band excitation in bulk measurements is consistent with spin gap behavior. The energy scale of the weakly coupled dimers in the Sc compound is perfectly coincident with that in the Fe compound. 
T. Masuda and G. J. Redhammer