The influence of experimental procedures on the structural and magnetic properties of RF sputtered Fe-N thin films

Fe-N thin films were fabricated on Si (1 0 0) by RF magnetron sputtering. The dependence of the structural and magnetic properties with varied nitrogen partial pressure (PN2), RF power and film thickness were systematically studied. The phase evolution from α-Fe(N) to ξ-Fe2N with increase of nitrogen partial pressure was seen. α″-Fe16N2 existed in the whole range of the nitrogen partial pressure. The research of in-plane magnetic anisotropy with different nitrogen partial pressure indicated that interstitial nitrogen atoms affected in-plane magnetic anisotropy in Fe-N system. With the increase of the film thickness from 50 to 730 nm, the saturated magnetization (Ms) decreases and the coercive force (Hc) increases. The good soft magnetic properties with Ms of 2223 emu/cm3 and Hc of 4 Oe were obtained at the optimized parameters of PN2, RF power and film thickness.