Dependence of soft magnetic properties and high frequency characteristics on film thickness for Ni75Fe25–ZnO nano-granular films

Abstract (Ni 75 Fe 25 ) 69 (ZnO) 31 granular films with various thicknesses were deposited by magnetron co-sputtering. The dependence of soft-magnetic properties and high frequency characteristics on film thickness was investigated systematically. Static magnetic research exhibits that thin films showed evident in-plane uniaxial magnetic anisotropy. And an interesting phenomenon was found that the magnetic anisotropy field H k increases with increasing film thickness t , which is not found in previous reports. However, no obvious variation with film thickness t was found for the coercivity ( H ce ) in easy axis and the coercivity ( H ch ) in hard axis. The measurements of high frequency characteristics show that the ferromagnetic resonance frequency f r increases with increasing film thickness t , which is ascribed to the increase of the magnetic anisotropy field H k . The films fabricated with appropriate thickness exhibits good high frequency properties and can be applied in the sensors operated in high frequency range.