First Principles Calculation of the Damping and Quasielastic Mode of DHCP-Pr

Starting with the interaction between the conduction and 4f electrons and taking the single-ion levels of Pr to be a singlet and a doublet, we have derived the dynamical susceptibility for dhcp Pr with Mori's memory function formalism [1]. The dynamics of the electron hole relaxation reflects itself in the damping mechanism of the magnetic excitations and leads to the quasielastic mode at finite wave vector Q, in contrast to the situation in ferromagnetic systems where the paramagnons contribute to the quasielastic mode at Q = 0. The finite Q response is due to the nesting properties of the Fermi surface. The result of first principles calculations using RAPW energy bands for quasielastic mode is, however, too small comparing to the experimental observations [2].