Room temperature ferromagnetism in Mn-doped zinc oxide nanorods prepared by hybrid wet chemical route

Highlights: → Mn-doped aligned zinc oxide (Mn:ZnO) nanorod-films were synthesized by hybrid wet chemical route. → Increase in atomic concentration of Mn (2.6-4.8 at%) did not affect vertical alignment. → No observable secondary phases were present in the films. → M-H hysteresis curves indicated that saturation magnetization (MS) increased with Mn concentration. → Substitution of Mn2+ in the Zn2+ site was responsible for the observed room temperature ferromagnetism. - Abstract: Mn-doped (2.6-4.8 at%) aligned zinc oxide (Mn:ZnO) nanorod-films were synthesized by hybrid wet chemical route onto glass substrates. The chemical composition, structural, microstructural and magnetic studies were performed to investigate the origin of observed room temperature ferromagnetism (∼0.11 μB/Mn) in these Mn doped ZnO nanorod-films. XPS studies indicated that incorporated Mn was in Mn2+ and Mn4+ states. Mn2+ atomic concentration was found to be significantly larger than Mn4+ concentration in all the samples. Disappearance of the Raman peak at ∼577 cm-1 arising due to the Zn interstitials may be related to the substitution of Mn2+ in the Zn2+ site with annealing. Thus, Mn metal inclusions as Mn2+ in the ZnO lattice are possibly responsible for such large magnetic moment in the films.