The dynamical susceptibility based on the Hubbard model of the body centered tetragonal lattice

We investigated the dynamical susceptibility related to the spin correlation within planes and that between planes based on the Hubbard model of the body centered tetragonal lattice (BCT) above the magnetic ordered temperature without a magnetic field. The dynamical susceptibilities are studied within the random-phase approximation. The criterion of the occurrence of the Neel order is also studied. We find that the expressions of the dynamical susceptibilities and the one of the criterion are more complicated than those of the simple cubic lattice because there are two atoms in the unit cell of the BCT. It is possible for us to analyze the neutron scattering and nuclear magnetic resonance experimental results in the BCT within the present approach. The present result is compared with the dynamical susceptibilities based on the Hubbard model of the hexagonal-close packed lattice (HCP). We predict that it is possible for us to observe two-component Knight shifts in URu2Si2 similar to those in UPt3 for muSR because the crystalline structure of U atoms in URu2Si2 is approximately BCT and because that in UPt3 is approximately HCP. (C) 2002 Elsevier Science B.V. All rights reserved.