Multi-layer composed of silica and titania alternately was formed on the surface of the iron powder. The powder dispersed in the ethanol solution containing ethoxide, and each layer was formed by using hydrolysis of the ethoxide.
Inteference of the visible light of the mono- or multi-layer coated powder was measured as a wave pattern by using the monochrometer.
The wavelength of the peaks and the bottoms of the wave pattern of interference of the multi-layer coated powder were controled by the composition of each coating solution.
Each wavelength of the peak and the bottom of wave pattern of the inteference of the multi-layer coated powder was nearly same as the simulated value.