Abstract
The Aerosol Deposition Method (ADM) has the possibility for fabrication of thick films at a high deposition rate at room temperature and under low vacuum. Therefore, Ni-Zn ferrite thick films, which possess high permeability at high frequencies, deposited by ADM are expected to be applied as noise suppressors in the quasi-microwave band. This paper describes the preparation and the high frequency properties of Ni-Zn-Cu ferrite thick films deposited by ADM. The powder for ADM was the calcined Ni-Zn-Cu ferrite powder with composition Ni0.25Zn0.65Cu0.12Fe1.98O4 prepared by the usual ceramics technique. The film with thickness of 10.7μm was obtained by the deposition for 4min and the deposition rate was estimated as 2.8μm/min. The relative density of the films was over 90%. The saturation magnetization of film after annealing at 1200°C was 6.33×10-5 Wb⋅m/kg and the coercvity was 0.94kA/m. These values were approximately equal to the values of the sintered body made from the powder. The maximum values of μr′ and μr″ were 200 and 70, respectively. The microwave absorption capabilities estimated by the product of μr″ and f (μr″⋅f) was 28 GHz (at 1 GHz) with the film annealed at 1200°C and this value was 75% larger than Fe-Si-Al flakes-polymer composite (16 GHz at 1 GHz), which is now used as a noise suppressor.
