Optimized microwave magnetic characteristics for patterned FeNi nanoparticle films manufactured by electric field-assisted deposition

The high-density FeNi nanoparticle films with strip structures were prepared by electric field-assisted deposition technique. The electric field of 10-40 kV was applied on the sputtering platform during thin film deposition in order to obtain superior in-plane soft magnetic properties. The dependence of magnetic properties and microwave behavior on electric field was investigated. It is found that these high-density films have magnetically easy-modulated characteristics, especially for the strip-patterned ones. Application of electric field is very effective to obtain stronger in-plane magnetic anisotropy field and higher saturation magnetization simultaneously for our samples. In this case, large permeability and high ferromagnetic resonance frequency are easily achieved when the strip-patterned films are used in a wide gigahertz range. The experimental results indicate that electric field-assisted deposition technique is one of the important and promising manufacture methods to prepare thin film materials with enhanced gigahertz electromagnetic wave properties.