High energy γ-ray Compton spectroscopy and electronic response of rare earth sesquioxides Er2O3 and Yb2O3

Abstract

In this paper, we present Compton profiles (CPs) of sesquioxides Er2O3 and Yb2O3 using 662 keV gamma-rays emitted by 20 Ci 137Cs source. To validate experimental momentum densities, theoretical CPs, energy bands, density of states (DOS), Mulliken's population of the both sesquioxides have been computed using linear combination of atomic orbitals (LCAO) method with pure and hybrid density functional theory (DFT). Present CP measurements confirm the applicability of hybrid (HF+DFT) approximation, namely WC1LYP, for predicting electron momentum densities and thereby electronic properties of such rare earth oxides. Energy bands and DOS unambiguously show insulating nature of the both compounds and the band gap values are found to be in tune with the available data. Further, the nature of bonding in Er2O3 and Yb2O3 is explained interms of the Mulliken's population and equally normalized CPs. Sharpness in Compton lines is also discussed in terms of localization of valence 5d states.