Paramagnetic Susceptibility of an Electron Gas in Alkali Metals

Abstract

The paramagnetic susceptibilily of an electron gas is calculated by making use of the Bohm-Pines description of electron interactions. The contribution from the long-range correlation to the susceptibility calculated by Pines is modified by using the larger cutoff wave vector of plasma oscillations and including the new contribution from the zero-point energy of plasma oscillations. The contribution from the second-order perturbation-theoretic calculation of the screened Coulomb interactions is obtained by a proper approximation. The contribution from the third-order perturbation-theoretic calculation of the interactions is obtained by a rather crude approximation. The comparisons of paramagnetic susceptibility with experimental values for alkali metals are made and the agreements for Li and Na are satisfactory. The volume dependences of paramagnetic susceptibility for alkali metals are examined by comparing the experimental results on the pressure dependence of the Knight shift with the Brooks calculations of the Fermi interaction.