ABSTRACT
Colloid elemental silver with small size of the particles formed in gelatin layers at development of silver halide photographic emulsions, was mentioned about more than 40 years ago in [1]. In a number of works, there are indications of existence of separate phase of the element silver consisting from nanoparticles and received as a result of photochemical reduction of Ag(I) salts, was appeared lately in the literature, in particular [2-11]. It has been noted that, before in [10, 11], at development of gelatin layers of silver halide photographic emulsions by alkaline water solutions containing tin(II) dichloride and some inorganic or organic substance form stable coordination compounds with Ag(I), formation of element silver occurs too. However, besides the gelatin layer is tinged brown or red but not black color as it takes place at standard development by using hydroquinone developers. It is significant that with increase of optical densities of the gelatin layer with an elemental silver, red tone in color of gelatin layer becomes more and more clearly expressed. The similar phenomenon takes place, when instead of silver halide AgHal in gelatin matrix there is such silver(I) compound as silver(I) hexacyanoferrate(II) Ag4[Fe(CN)6]. Whether this totality of particles is a novel phase of element silver? Or it is only a variety of known phases of the given simple substance? These questions remains till now, opened and deserves special consideration.
