Soft Magnetic Properties of FeN/FeBN Multi-layers

stract-The magnetic and structural properties of multilayered FeN/FeBN films prepared by dual-target sputtering were investigated. Laminating FeBN films with FeN films increases the electrical resistivity (R) by up to 200 μΩ-cm, decreases slightly the saturation magnetization and results in excellent soft magnetic properties (coercivity ≤0.2 Oe and permeability ≥1000) over a wide range of film thickness combinations; this despite the fact that single FeBN films have a high R of about 400 μΩ-cm, a B
_s
of about 12 kG and semi-hard magnetic properties with perpendicular magnetic anisotropy. SEM observations suggest that the soft magnetic properties of FeN/FeBN multilayer films originate in their in-plane anisotropy and the fine grain texture of the films. Despite film thicknesses exceeding 2 μm, a permeability of about 1000 was maintained even near 100 MHz. The extended frequency response of the permeability is without doubt due to the increased electrical resistivity of films when laminated with FeBN.