DISPERSION OF CRYSTAL-FIELD EXCITATIONS IN ND2CUO4 AND PR2CUO4

Energies and intensities of transitions between the lowest crystal fie ld levels of the rare-earth ions are investigated by neutron inelastic scattering in a wide range of reciprocal space of single-crystal samp les. At low temperatures the investigated excitations showed clear dis persion. The magnitude of the observed dispersion of the crystal field excitations essentially decreases approching room temperature, exhibi ting different temperature dependence in the two compounds.