Eur. Phys. J. B 29, 377-384 (2002)
https://doi.org/10.1140/epjb/e2002-00321-8

CEF nature of the magnetic excitations in ordered HoNi₂B₂C

¹ Laboratory for Neutron Scattering, ETH Zürich & Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
² Ames Laboratory, Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
³ Laboratoire Léon Brillouin, CEA/CNRS-Saclay, 91191 Gif-sur-Yvette, France

Corresponding author: ^a nordal.cavadini@psi.ch

Received: 25 February 2002
Revised: 13 May 2002
Published online: 14 October 2002

Abstract

The magnetic excitations in the antiferromagnetic phase of HoNi₂B₂C are studied by inelastic neutron scattering on single crystals for the first time. Spectra measured at constant T=2 K along symmetry directions of the reciprocal space are well explained in terms of crystal electric field (CEF) magnetic excitons within the J=8 ground state multiplet of Ho³⁺. Very modest bandwidth with planar energy dispersion describes the magnetic exciton dynamics. A perturbative model approach consisting of the CEF states in the effective exchange mean-field provides a simple but applicable characterization of the experimental observations. The microscopic determination of the relevant exchange parameters is discussed in connection with previous works on the subject.