Change in the Pauli susceptibility of Li on melting

Abstract

The Pauli susceptibility ${\ensuremath{\chi}}_{P}$ of Li metal was measured below and above the melting point at constant pressure. ${\ensuremath{\chi}}_{P}$ increased by (0.8 \ifmmode\pm\else\textpm\fi{} 0.6)% on melting. The corresponding increase at constant volume was deduced, by using the volume dependence of ${\ensuremath{\chi}}_{P}$ for solid Li, as (0.7 \ifmmode\pm\else\textpm\fi{} 0.6)%. From the observed change in the Knight shift on melting, the change in the electronic charge density at the nucleus ${P}_{F}$ was also derived. ${P}_{F}$ decreased by (1.9 \ifmmode\pm\else\textpm\fi{} 0.6)% on melting at constant volume. The observed value of ${P}_{F}$ and ${\ensuremath{\chi}}_{P}$ for solid Li does not collapse to the nearly-free-electron value, which was once postulated to characterize the liquid-metal state.