A Study of State of Iodide Ions on AgCl Grains through Their Physical Properties

Abstract

The state of iodide ions on cubic AgCl grains was studied by measuring and analyzing the physical properties of the grains in emulsions, to which an aqueous solution of KI was added. It was judged that iodide ions were adsorbed on the grains (1), and then involved in the formation of AgI (2) and AgClI (3). It was indicated that the addition of small amount of iodide ions (-1 mol%) to an AgCl emulsion caused the increase in the ionic conductivity of the grains by more than two orders of magnitude, converted the diffusion-limited kinetics into reaction-limited one for the electron-trapping process on the grain surface, and enhanced the electron-trapping by sulfur sensitization centers.