Structural Peculiarities and Magnetic Properties of FeNi Films and FeNi/Ti-Based Magnetic Nanostructures

Fe₁₉Ni₈₁ films and Fe₁₉Ni₈₁/Ti-based nanostructures were prepared by rf-sputtering. The thicknesses of FeNi samples were below and above the critical thickness of the transition into "transcritical" state which controls perpendicular magnetic anisotropy and there fore the low coercivity and magnetic softness. FeNi/Ti-based magnetic nanostructures were designed with focus on high-frequency applications. Their structure was studied by X-ray diffraction. The magnetic properties and magnetic domains were investigated by mag neto-optical Kerr effect and Bitter technique. The increase of the grain size was observed with an increase of the total thickness of the films. It was shown that [FeNi(50 nm)/Ti(6 nm)]₇/FeNi(50 nm) nanostructures have the lowest coercivity and interesting struc tural features which can be responsible for the improvement of their magnetic properties.