Effects of magnetic flux densities on microstructure evolution and magnetic properties of molecular-beam-vapor-deposited nanocrystalline Fe30Ni70 thin films

• With increasing magnetic flux density, average particle size of films decreased.
• With increasing magnetic flux density, surface roughness of thin films decreased.
• With increasing magnetic flux density, short-range ordered clusters increased.
• With increasing magnetic flux density, the coercive forces of thin films reduced.
• With increasing magnetic flux density, soft magnetic properties are improved.

Nanocrystalline Fe30Ni70 (in atomic %) thin films were prepared by molecular-beam-vapor deposition in magnetic fields with different magnetic flux densities. The microstructure evolution of these thin films was studied by atomic force microscopy, transmission electron microscopy, and high resolution transmission electron microscopy; the soft magnetic properties were examined by vibrating sample magnetometer at room temperature. The results show that all our Fe30Ni70 thin films feature an fcc single-phase structure. With increasing magnetic flux density, surface roughness, average particle size and grain size of the thin films decreased, and the short-range ordered clusters (embryos) of thin films increased. Additionally, the magnetic anisotropy in the in-plane and the coercive forces of the thin films gradually reduced with increasing magnetic flux density.