The structure and magnetic properties of Fe- N thin films

200 nm Fe-N thin films deposited on glass substrates by RF sputtering were vacuum annealed at 250–350C under 12000 A/m magnetic field. Heat treatment was effective in improving the soft magnetic properties of the Fe-N film. When the nitrogen content was in the range of 5–7 at. %, the thin films consisted of α′ + α″ after heat treatment and had excellent soft magnetic properties of 4πMs = 2.4 T, Hc < 80 A/m, μr = 1500 under 2–10 MHz. The properties of the films meet the needs of a write head material used in the dual element GMR/inductive heads. The fromation mechanism and lattice constants of the a’ phase in Fe-N thin film are different from Jack’s results obtained from y-a1 transformation in bulk samples. The linear relationship between a, c and CNα′ for thin film was obtained as