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

We report the electronic structure studies of well-characterized polycrystalline Zn1-xFexO (x = 0.0, 0.01, 0.03 and 0.05) nanorods synthesized by a co-precipitation method using 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 replace Zn ions in the ZnO matrix. Linear combination fittings at Fe K-edge demonstrate that Fe is in a mixed-valent state (Fe3+/Fe2+) with a ratio of similar to 7:3 (Fe3+ : Fe2+). XAFS data are successfully fitted to wurtzite structure using IFEFFIT and Artemis. The results indicate that Fe substitutes Zn site in the ZnO matrix in tetrahedral symmetry.