FERROMAGNETISM IN SEMICONDUCTOR C–Ni FILMS AT DIFFERENT ANNEALING TEMPERATURE

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