Influence of the core-hole effect on optical properties of magnesium oxide (MgO) near the Mg L-edge region

The influence of the core-hole effect on optical properties of magnesium oxide (MgO) is established through experimental determination of optical constants and first-principles density functional theory studies. Optical constants ( δ and β ) of MgO thin film are measured in the spectral region 40 – 300   eV using reflectance spectroscopy techniques at the Indus-1 synchrotron radiation source. The obtained optical constants show strong core exciton features near the Mg L-edge region, causing significant mismatch with Henke's tabulated values. On comparing the experimentally obtained optical constants with Henke's tabulated values, an edge shift of ∼ 3.0   eV is also observed. Distinct evidence of effects of core exciton on optical constants ( δ and β ) in the near Mg L-edge absorption spectra are confirmed through first-principles simulations.

Source: Journal of Synchrotron Radiation - March 14, 2018 Category: Physics Authors: Sinha, M. Modi, M.H. Ghosh, H. Yadav, P.K. Gupta, R.K. Tags: synchrotron radiation soft X-ray magnesium compound core-hole effect optical property research papers Source Type: research