Probing Local Electronic Structure of Amorphous MgO Thin Films by Angle Dependent Soft X-ray Absorption Spectroscopy: Impact of Heavy Ions

Abstract

The present study investigates the local electronic structures of amorphous thin films before and after 100 MeV O 7+ ion irradiation by using the angle-dependent near-edge X-ray absorption fine structure (NEXAFS) measurements at O and Mg K -edges. X-ray diffraction study reveals that as-grown film is amorphous in nature and it remains unaltered after ion irradiation. Post-irradiated film exhibits the onset of surface modifications as revealed from X-ray reflectivity measurements. The spectral features appearing in O K - and Mg K -edge NEXAFS measurements for pristine and irradiated films exhibit the characteristics of MgO. Less intense spectral features in the irradiated thin films are evident due to distortion in Mg 2+ ion coordination induced by the bombardment of 100 MeV O 7+ ions.