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 similar to 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 degrees C in an air atmosphere to improve the crystallinity of the films. NEXAFS studies on Fe L-2,L-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,L-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.