A POSITRON-ANNIHILATION STUDY OF THE ELECTRONIC-STRUCTURE OF CEB6

The two-dimensional angular correlation of electron-positron annihilat ion radiation (2D ACAR) from the heavy-fermion dense Kondo system CeB6 was measured. The anisotropies of the measured momentum spectra were in reasonable agreement with those of model spectra based on the Fermi -surface topology suggested by band-structure calculations and de Haas -van Alphen measurements. However, the related k-space densities, obta ined by an LCW analysis, were far removed from those expected from the Fermi-surface topology. The use of a recently developed filter proced ure, designed to remove the characteristic long-range distortions that are frequently encountered in such LCW spectra, provided a much impro ved image of the Fermi-surface features.