Magnetic excitations in the cubic antiferromagnet ErCu

Abstract
The magnetic excitations of the antiferromagnetic compound ErCu (cubic CsCl structure) have been studied by inelastic neutron scattering at 4.3 K. The data are analysed within a generalized susceptibility model, taking into account the crystal field Hamiltonian and anisotropic bilinear exchange. Interactions up to the fourth neighbours seem sufficient to describe the dispersion relations; the addition of higher order interactions or magnetoelastic terms improves the fit of the spin wave energy gaps