Soft Magnetic Properties of Fe/Fe-N Multilayered Films Prepared at Various Sputtering Gas Pressures

Fe/Fe-N multilayered films were prepared by alternation of Fe sputtering at various Ar gas pressures and ECR nitrogen plasma exposure, and the structure and magnetic properties of the resulting films were investigated. Growth of columnar structures was observed in Fe film prepared at high Ar gas pressure. Fe/Fe-N multilayered films with an Fe layer prepared at low Ar gas pressure have a low Hc and high Bs. X-ray diffraction suggests that the lattice spacing of Fe (110) and the compressive stress in these films increase with decreasing Ar gas pressure. These structural changes are caused by nitrogen diffusion from the Fe-N layer into the Fe layer. Nitrogen exists in solid solution in Fe layers prepared at low Ar gas pressure, and in the form of nitrides in Fe layers prepared at high Ar gas pressure.