Impact of Annealing on Metal–Oxygen Hybridization Process in Zinc Ferrite Thin Films Studied by Angle Dependent Soft X-Ray Absorption Spectroscopy

Abstract

Herein, we report the impact of thermal annealing on the metal (Fe-3d)-oxygen (O-2p) hybridization in zinc ferrite thin films using the angle-dependent near-edge X-ray absorption fine structure (NEXAFS) technique. Zinc ferrite thin films of thickness ~ 100 nm are grown on MgO (200) substrates using radio frequency sputtering. Further, these as-grown films are annealed at temperatures 200, 400, and 600 °C in an air atmosphere to improve the crystallinity of the films. NEXAFS studies on Fe L_2,3-edge and O K-edge reveal the importance of thermal annealing on the modification of the electronic structure of zinc ferrite films. Angle-dependent NEXAFS studies on Fe L_2,3-edge suggest that the variation in electronic structure caused by the metal–oxygen hybridization in Zinc Ferrite is influenced by the film’s crystallinity through the annealing process. Further, the nature of metal–oxygen hybridization in zinc ferrite is confirmed by the O K pre-edge angle-dependent NEXAFS studies.