Structural, magnetic properties and photoemission study of Ni-doped ZnO

Abstract

Nickel-doped ZnO (Zn 1− x Ni x O) have been produced using rf magnetron sputtering. X-ray diffraction measurements revealed that nickel atoms were successfully incorporated into ZnO host matrix without forming any detectable secondary phase. Ni 2p core-level photoemission spectroscopy confirmed this result and suggested Ni has a chemical valence of 2+. According to the magnetization measurements, no ferromagnetic but paramagnetic behavior was found for Zn 0.86Ni 0.14O. We studied the electronic structure of Zn 0.86Ni 0.14O by valence-band photoemission spectroscopy. The spectra demonstrate a structure at ∼2 eV below the Fermi energy E F, which is of Ni 3d origin. No emission was found at E F, suggesting the insulating nature of the film.