Momentum-Transfer Dependence of the Near Edge Structure of Li

Abstract

The dynamic structure factor S ( q , ω) of the K -electrons in Li metal was measured in an inelastic X-ray scattering experiment with 0.8 eV resolution using synchrotron radiation. The near edge structure of S ( q , ω) over an energy range of 30 eV from the edge has been obtained for values of q a of 0.22, 0.38, 1.17 and 1.55, where \(\hbar q\) is the momentum-transfer and a is the K -electron orbital radius. The overall shape of the near edge region changes remarkably with q . On the other hand, the near edge fine structure varies hardly with q and is similar to the soft X-ray absorption near edge fine structure over a wide range of q . This weakly q -dependent fine structure can be attributed to the band structure effecting the final state electron symmetry, while the strongly q -dependent overall shape may be influenced mainly by the initial momentum distribution of the K -electrons.