Polycrystalline iron nitride films fabricated by reactive facing-target sputtering: Structure, magnetic and electrical transport properties

Abstract

Structure, magnetic and electrical transport properties of the reactive sputtered iron nitride films fabricated at different substrate temperatures (Ts) and nitrogen flow rates (FN2) were investigated systematically. The single-phase polycrystalline γ′-Fe4N film was obtained at FN2 = 20 sccm and Ts = 450 °C. The films are soft ferromagnetic at room temperature. The electrical resistivity (ρ) of the films fabricated at different FN2 and Ts decreases with the decreasing temperature, showing a metallic behavior. Meanwhile, a variety of magnetoresistance (MR) behaviors were observed depending on the applied magnetic field and measuring temperature. It can be deduced that the complex MR behaviors are dominated by Lorentz force, spin-orbit interaction, and weak localization effect.