In this work, the magnetic properties and the electrical conductivity of carbon–nickel composite films deposited at different deposition times 50–600 s were investigated. The films were grown by radio frequency magnetron co-sputtering on glass substrates at room temperature. The nickel concentration in the films are effected by changing of the deposition rate and measured by energy dispersive X-ray studies. Values of coercive field were measured under both increasing and decreasing applied magnetic field. It is shown that the coercive field strongly dependent on both the nickel concentration and nickel nanoparticle size and at 180 s films has maximum value 68.04 (Oe). The difference in the coercive fields increased for films deposited from 50 to 180 s and then decreased for films deposited at 600 s. The ID/IG ratio of Raman spectra would indicate the presence of higher sp2 bonded carbon in the films deposited at 180 s. For entire temperature range (15–500 K), the electrical conductivity of films deposited up to 180 s increases and then from 180 to 600 s it decreases. These observations are in a good agreement with the field emission scanning electronic microscopy (FESEM) images.
