Magnetisation dynamics of YbIr2Si2

The two crystallographic modifications of YbIr2Si2 are supposed to be located on either side of a quantum phase transition. We here report on inelastic neutron scattering experiments investigating the magnetisation dynamics in the paramagnetic state. The observed magnetic scattering in the energy range of about 15-40meV has been attributed to crystalline electric field (CEF) transitions. We relate our findings to the magnetic properties of the non-Fermi-liquid (NFL) YbRh2Si2. (c) 2006 Elsevier B.V. All rights reserved.