Abstract

Silver chemical compounds are attributed to the number of the most widespread photochromic materials. The ideas, underlying photochemical processes arc quite clear. At the same time metallic colloidal silver, drawing attention due to its ability to change colour, was. never considered as photorecording material. The latter is determined by the high energy threshold of radiation, that may cause rapid photoinduced changes of colloid optical properties. Physical mechanisms of photochromizrn of metallic colloids fundamentally differ from that of chemical compounds and have not been studied so far. In the present paper we propose the explanation for the origin of photochromic reactions in this type of media.

© 1996 IEEE