Calculation of the electron momentum density and Compton scattering measurements for nickel

Abstract

The (100), (110) and (111) directional Compton profiles of single crystals of nickel have been measured using 59.54 keV 241Am gamma -rays at a 170 degrees scattering angle and a well defined scattering vector. The electron momentum distribution and Compton profiles in nickel have also been calculated on the basis of a self-consistent augmented-plane-wave method within the local-density approximation including a correlation correction term. A quantitative comparison between experimental and theoretical directional Compton profiles shows good agreement and reveals some accurate information about the Fermi surface. Excitations due to nonlocal correlation effects from contributing parts to noncontributing parts of the energy bands are very clearly seen along the (100), (110) and (111) directions. The calculation also reproduces quite well the main features of the observed anisotropies, typically within the experimental error margins, although it slightly overestimates their magnitude.