On the formation of silver specks in silver halide crystals

Abstract

This theoretical study summarizes ionic and electronic processes in AgBr crystals and the influence of its results on photographic process. It deals with the importance of surface generated interstitials which Gurney and Mott left untouched because of the non-availability of sufficient data at that time. The magnitude of various parameters,e.g., mean intra-electron-ion distance in a latent image site, the rate of neutralization of Ag+ ion with trapped electron and capture cross-section for combination of Ag+ ion with the trapped electron, etc. (as desired for understanding the theory of photographic process) are calculated at different temperatures. The results when used in our earlier papers (Singh and Sharma, 1974 and 1975, and Singh 1975) for calculating charged particle track characteristics theoretically were found to give good agreement with the published experimental data (Della Corteet al 1953 and Dyer and Hechman 1967). A model for the mechanism of latent image formation (silver speck) is discussed.