I. Introduction
NiZn ferrite films prepared by spin-spray ferrite plating from an aqueous solution at 90 °C have high permeability even up to the gigahertz range [1]. The films directly deposited onto a strip line on an epoxy printed circuit board suppressed the conduction noise up to 3 GHz strong enough for actual utilization as gigahertz noise suppressors [2]. Adding to the oxidizing solution (which raises ) not only enhanced natural ferromagnetic resonance frequency (a criterion for usable frequency) in the ferrite plating, but also increased film deposition rate up to 67 nm/min without degrading the film quality [3]. This is quite advantageous for applying to the noise suppressors. In this study, we measured X-band ferromagnetic resonance (FMR), including standing spin-wave resonance (SWR) modes [4], in order to investigate the magnetic homogeneity in two types of the films, one prepared using the adjusting solution of (called hereafter -used film), the other prepared without adding (called conventional film).