High moment soft FeCoN/NiFe laminated thin films

Fe₇₀Co₃₀N/Ni₅₅Fe₄₅ laminated thin films were sputtered onto the glass and Si wafers by dc magnetron sputtering using different N₂/Ar gas mixtures. The structure and magnetic properties of the films were investigated by the XRD, TEM, and B-H loop tracer. A soft FeCoN/NiFe laminated thin film with a B_S of 2.40 T and a well-defined uniaxial anisotropy has been achieved at the optimized conditions. It was found that the incorporation of nitrogen in the FeCo films does not change the lattice constant of FeCo, but it does change the film stress from compressive to tensile. It is believed that the combination of tensile stress and positive magnetostriction maintains the softness of FeCoN/NiFe laminated thin film beyond 1 μm.