Ni-defective value and resistivity of sputtered NiO films

Abstract The lattice constant of the rhombohedral NiO films is larger than that of the bulk and depends on the O 2 partial pressure ( P O ) during the reactive sputtering; the axis angle is close to that of the bulk. The anisotropy of magnetic susceptibility χ is observed, and the average value (1.2×10 −9 H/m) is the same as that of the bulk. Rutherford back scattering (RBS) analysis shows that the NiO films are confirmed to be non-stoichiometric and the Ni-defective value γ in Ni 1− γ O films is 0.14–0.23; γ increases with P O . The electric resistivity ρ (∼1 Ω cm) of the NiO film is four orders of magnitude smaller than that of bulk NiO, and decreases slightly with increasing γ .