Electronic structure studies of Fe- ZnO nanorods by x-ray absorption fine structure

TL;DR

This study investigates the electronic structure of Fe-doped ZnO nanorods using X-ray absorption fine structure, revealing Fe substitution at Zn sites and mixed valence states, with implications for their structural and electronic properties.

Contribution

It provides detailed insights into the local electronic and structural environment of Fe in ZnO nanorods, highlighting Fe substitution and valence states using XAFS analysis.

Findings

Fe ions replace Zn ions in the ZnO lattice.

Fe exists in mixed valence states (Fe3+/Fe2+).

Fe substitutes Zn in tetrahedral symmetry.

Abstract

We report the electronic structure studies of well characterized polycrystalline Zn_{1-x}Fe_xO (x = 0.0, 0.01, 0.03, and 0.05) nanorods synthesized by a co-precipitation method through x-ray absorption fine structure (XAFS). X-ray diffraction (XRD) reveals that Fe doped ZnO crystallizes in a single phase wurtzite structure without any secondary phase. From the XRD pattern, it is observed that peak positions shift towards lower 2\theta value with Fe doping. The change in the peak positions with increase in Fe contents clearly indicates that Fe ions are replacing Zn ions in the ZnO matrix. Linear combination fittings (LCF) at Fe K-edge demonstrate that Fe is in mixed valent state (Fe3+/Fe2+) with a ratio of ~ 7:3 (Fe3+:Fe2+). XAFS data is successfully fitted to wurtzite structure using IFEFFIT and Artemis. The results indicate that Fe substitutes Zn site in the ZnO matrix in tetrahedral symmetry.