Electronic structure of layer type tungsten metal dichalcogenides WX2 (X = S, Se) using Compton spectroscopy: Theory and experiment

In this paper, we report the first ever experimental Compton profile study of WS2 and WSe2 employing 20 Ci Cs-137 Compton spectrometer. To interpret our experimental data, the electronic properties of these compounds have been determined by linear combination of atomic orbitals, full potential linearised augmented plane-wave and spin polarised relativistic Korringa-Kohn-Rostoker (SPR-KKR) schemes. The band structure calculations show that both the WS2 and WSe2 are indirect-gap semiconductors. The SPR-KKR calculations are found to be relatively in poor agreement with the experimental electron momentum densities. The relative nature of bonding in both the dichalcogenides is explained in terms of equalvalence-electron-density profiles, Mulliken's population and valence band charge densities. (C) 2008 Elsevier B.V. All rights reserved.