Tunable resonance frequency of wavelike FeNi nanofilm using a double-layer structure

Abstract A variety of triangular wavelike FeNi films have been obtained on the annealed single-crystalline Al2O3 substrate by magnetron sputtering and photolithography. Nanoscale patterns and microscale stripes in double-layer FeNi nanofilm have also been studied. Properties relating to the morphology, and static and dynamic magnetic properties of materials were measured by AFM, SEM, vibrating sample magnetometers, and vector network analyzers. The surface of the annealed sample was wavy, and its wavelength and peak were 80 nm and 15.4 nm, respectively. Lithography formed 15-μm-wide lines on the surface. Compared with nano-scale patterns, the micro-scale stripes, and overlay patterns, fr increased to 4.5 GHz after superposition and FeNi was used as a soft magnetic material. Hc should have been small but, after superimposing the pattern, increased significantly. Hc along the easy axis increased to 18 Oe and that along the hard axis to 50 Oe. This was related to the coupling effect of the multilayer film.