PLASMON ABSORPTION OF GOLD NANOPARTICLES AND THEIR MORPHOLOGIES OBSERVED BY AFM

We have studied the effect of heat treatment on Au-island film prepare d by a sputtering method, atomic force microscopy (AFM), and UV-VIS sp ectrophotometry. The structure and absorption spectrum of Au-island fi lm are significantly changed by heat treatment, which corresponds to t he visible color change from blue to red. In order to elucidate the re lation between the structural and optical changes, we have simulated t he change of spectrum using the Maxwell-Garnett theory. The calculated spectra are qualitatively in agreement with the experimental spectra.