Determination of the crystalline electric field in the tetragonal symmetry rare earth intermetallic HoAg 2

Abstract

Inelastic neutron scattering and paramagnetic susceptibility techniques have been jointly employed to study the Crystalline Electric Field (CEF) coupling in the intermetallic compound HoAg 2, which crystallizes within the MoSi 2-type structure. The observed inelastic scattering spectra exhibit a large number of well defined CEF transitions from 0.7 to 15 meV in excitation and de-excitation processes according to the temperature. A change in sign of the anisotropy of the paramagnetic susceptibility is observed around 75 K and nonlinear temperature dependences are measured at low temperatures for the reciprocal susceptibility. Despite the number of characteristic features to be described, fitting the results of only one of these two experiments does not lead to a unique set of CEF parameters. On the contrary cross checks between the two techniques are necessary to determine a common solution. This consistent determination reveals a weak second-order CEF contribution and suggest several consequences on the magnetic and magnetoelastic properties.