Functional properties of nickel cobalt oxide thin films

• DOI: 10.1016/j.tsf.2011.08.067
• Publication Date: 2011-08-25T20:05:25Z
• Authors: F. Iacomi; G. Calin; C. Scarlat; M. Irimia; C. Doroftei; M. Dobromir; G.G. Rusu; N. Iftimie; A.V. Sandu
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract Cobalt–nickel oxide films of known stoichiometry (x = Ni / (Co + Ni) = 0.30–0.63) were deposited on glass slides by using a spin-coating method and were UV irradiated for 2 h. The structure and morphology of thin films evidenced nanocrystalline spinel structures. Thin films with x = 0.63–0.5 have a mixed phase structure and good sensing properties for ethanol. Thin films with x = 0.30–0.40 have a single spinel phase, are ferrimagnetic and highly conductive at 300 K and have magnetoresistance ratios of 5–8%. Four-probe measurements indicate an insulator–metal transition at temperatures slightly below ferromagnetic Curie temperature. Metallic Ni and Co particles improve thin film functional properties.