Atomic form-factor measurements in the low-momentum transfer region for Li, Be, and Al by inelastic x-ray scattering
A. Alatas, A. H. Said, H. Sinn, G. Bortel, M. Y. Hu, J. Zhao, C. A. Burns, E. Burkel, and E. E. Alp

We report measurements of the atomic form factor of lithium, beryllium and aluminum single crystals at low momentum transfers (Q=1.6-50$\;$nm$^{-1}$) from the intensity of phonons observed by inelastic x-ray scattering. Comparing to Hartree-Fock calculations, the form factor deviates significantly in the case of lithium and beryllium around k$_{F}$. These deviations can be mostly understood on the base of electron redistribution by a pseudopotential. The influence of multiple scattering due to coherent phonon scattering and possible deviations from the adiabatic approximation are also discussed.

© 2008 The American Physical Society.