Coverage Dependence of the Local Density of States at the Fermi Energy: Li Adsorbed on Ru(001)

Abstract

The local density of states (LDOS) of Li on a Ru surface has been determined between very low and 0.15 monolayer coverage. $\ensuremath{\beta}$-decay detected nuclear magnetic resonance has been employed to measure the spin lattice relaxation rate between 200 and 1250 K. The $\mathrm{LDOS}({E}_{F},0)\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.13(1)\phantom{\rule{0ex}{0ex}}{\mathrm{eV}}^{\ensuremath{-}1}{\AA{}}^{\ensuremath{-}3}$, which is 0.6 of the bulk metallic value supporting a view of an at most weak ionic bond. No coverage dependence of the LDOS is seen in the regime investigated. Thus the adsorbate wave functions do not overlap. The LDOS provides a benchmark against which theoretical approaches must be measured.