Theoretical Magnetic Susceptibilities of Metallic Lithium and Sodium

Abstract

The magnetic susceptibilities of metallic lithium and sodium are computed by using the best available theoretical information. Bardeen's effective masses and exchange and correlation terms are included. This procedure appreciably affects the theoretical paramagnetism for free electrons, giving results considerably different from those obtained from Pauli's equation with the assumption that the electrons are perfectly free and that exchange and correlation terms may be neglected. The final computed susceptibility for sodium is close to the observed value, but that for lithium is about twice the highest experimental one. The possible sources of error are investigated and it is concluded that the presence of a quartic term in the expansion of the one-electron energy parameter in terms of a power series in the electron wave number would be sufficient to account for the deviation. The level density curves obtained from x-ray emission curves are discussed and it is concluded that all details of these curves cannot be explained on the basis of the simple picture ordinarily used.