Investigations of anisotropy of the electronic density in KC 8 by synchroton X-ray Compton scattering

Abstract

Extensive experiments have been performed to determine the electronic behavior of the outer alkali electron in the stage one heavy alkali metal GIC to test both available band structure calculations (1,2). The discrepancy in the experimental results is very large, leading to prediction of large (3,5) or small (4) charge transfer. Within impulse approximation, the Compton profiles are used to determine the electron momentum distribution of the solid along selected directions. As it works in momentum space, the inelastic scattering is a very sensitive test of the ground-state calculated wave-functions. Compton profiles have been measured, using the high resolution spectrometer from the LURE synchroton source, with intercalated HOPG samples. The special features of the conduction band of KC 8 are discussed in comparison with theoretical band structure calculations (1,2). For more accurate check, we need the theoretical Compton profiles based on calculated wave-functions.