Magnetic excitations of single-crystal PrBa2Cu3O6.2

Measurements of the low-energy magnetic excitations in single-crystal PrBa2Cu3O6.2, and in YBa2Cu3O6.2 for comparison, have been performed using inelastic neutron scattering. An excitation with weak dispersion is seen, which is compared to a spin-wave model based on the lowest lying crystal field levels of the Pr ion, and including the effect of an anisotropic coupling to the Cu magnetic moments, as well as a Pr-Pr exchange interaction. (C) 2000 Elsevier Science B.V. All rights reserved.