Crystal electric field levels in Ho2PdSi3 studied by inelastic neutron scattering in magnetic fields

The series R2PdSi3 (R=rare earth), has been found to exhibit rich magnetic phenomena resulting from the interplay between RKKY interaction, crystal-electric field effects and geometric frustration. Except for the Ho2PdSi3 compound the second order crystal electric field parameter dominates the magneto-crystalline anisotropy. The Ho2PdSi3 compound which orders antiferromagnetically at TN=7.7 K offers therefore the opportunity to study the influence of the higher order crystal electric field parameters. We performed inelastic neutron scattering experiments on a large Ho2PdSi3 single crystal in magnetic fields up to 13 T at the cold triple axis spectrometer (PANDA, FRM-II). In applied magnetic fields above the critical field for the transition into FM induced state, the crystal electric field levels undergo Zeeman splitting; and the energy shift varies from approx. 0.1 meV/T to 0.3 meV/T, implying the influence of the higher order crystal field parameters. In this contribution we present and discuss the results of the inelastic neutron scattering experiments and give a proposal for the crystal electric field level scheme