Fabrication and magnetic properties of Sol-Gel derived NiZn ferrite thin films for microwave applications

Abstract

We present a new solution-phase, sol-gel based spin-coating method to fabricating high quality, nickel zinc ferrite (NZFO) thin films. The effect of annealing temperature on the microstructure, static magnetic properties and X-band FMR linewidth and resonance field was investigated. Furthermore, the effect of composition on these properties was explored in films with the formula NixZn(1-x)Fe2O4 (where x = 0 to 1 in 0.1 increments). Films annealed at the highest annealing temperature of 1100 ?C were found to have the highest saturation magnetization and coercivity, as well as the lowest FMR linewidths. Films with the composition Ni0.3Zn0.7Fe2O4 were found to have the lowest linewidths along with favorable magnetic properties for microwave applications. The champion film showed an FMR linewidth of 93 G, corresponding to a low Gilbert damping coefficient of α = 0.003, a saturation magnetization of 330 emu/cm 3 , and a coercivity and anisotropy field of 14 and 62 Oe respectively.