In this work, the microstructure and magnetic properties of carbon–nickel (C–Ni) composite ¯lms annealed at di®erent temperatures (300–1000C) were investigated. The ¯lms were grown by radio frequency magnetron sputtering on quartz substrates at room temperature. The nickel concentration in the ¯lms are a®ected by changing of the value of evaporation nickel atoms and measured by Rutherford backscattering spectroscopy (RBS). Values of coercive ¯eld were measured under both increasing and decreasing applied magnetic ¯eld. It is shown that the coercive ¯eld of ¯lms strongly dependent on the annealing temperature and at 500C ¯lms has maximum value of 93.67 Oe. The di®erence in the coercive ¯elds increased for ¯lms annealed from 300 to 500C and then decreased from 500 to 1000C. The ID/IG ratio of Raman spectra would indicate the presence of higher sp2 bonded carbon in the ¯lms annealed at 800C.
