STRONG ANISOTROPY IN HYBRIDIZATION-INDUCED RELAXATION OF MAGNETIC EXCITATIONS IN U-3+ SYSTEMS

Sharp magnetic excitations typically are not observed in neutron inelastic scattering experiments in uranium systems having partially delocalized 5f electrons such as the incipient heavy fermion systems UP and UAs. Exceptions are USb and UTe. For UTe, Lander et al. recently found dispersion relations and damping that are very anisotropic, with line-width increasing moderately along [q q q], but very strongly along [q q̄ 0]. We have now applied our relaxation theory to UP, UAs and UTe, and find excellent agreement with experiment. For UTe a strongdifference in broadening behavior with q arises because the intensity distribution among modes is strongly q-dependent. We regard the agreement with experiment for the highly anisotropic broadening of the magnetic excitations in UTe asproviding an especially significant verification of the validity of our physical picture and theoretical methodology. © 1990.