ZnO nanorods decorated with nanocrystalline (nc)Au Particles:Electronic structure and magnetic behaviours

Electronic structures and magnetic behaviours of zinc oxide nanorods (ZnO-NRs)decorated with nanocrystalline “Au”-particles (nc-Au)have been studied using different spectroscopies, superconducting quantum interference device-type magnetometer and plane wave pseudopotential density functional theory calculations. The presence of intrinsic defects viz. zinc interstitials (Zn_i)and/or oxygen vacancies (V_O)are established using different spectroscopies measurements. Ultraviolet photoelectron spectroscopy and valence band photoemission spectroscopy suggests that the valence band density of states of O 2p - Zn 4sp hybridized states of nc-Au/ZnO-NRs is higher than pure ZnO-NRs that could be correlated with its higher ferromagnetic behaviour. An enhanced room temperature ferromagnetism has been observed when nanocrystalline (nc)gold (Au)particles are decorated on the surface of ZnO-nanorods (ZnO-NRs). This enhanced magnetic moment in nc-Au/ZnO-NRs comes from the metallic electrons of nc-Au that induces large orbital magnetic moment at the nc-Au/ZnO-NR interface. Theoretical calculations shows the enhancement of the density of states at the valence band region of ZnO with a decoration of optimum content nc-Au particles along with the increase of oxygen vacancies in nc-Au/ZnO-NRs; that further confirms the enhancement of magnetization.