REVERSIBLE PHOTOCHROMISM OF SOL-GEL SIO2-AGCL FILMS

Glass films containing silver chloride were prepared by the sol gel me thod. The films darkened upon irradiation with sunlight or UV-light an d were bleached reversibly by exposed to nitric acid vapors. The mecha nism of the reversible bleaching is deduced from optical spectra, x-ra y diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). The si lver chloride particles that were dispersed isotropically before expos ure to light acquire a preferred orientation after repeating darkening and bleaching cycles.