The modification of the crystals surface structure by epitaxial growth

One of the most important parameters defining the quality of silver halide photographic materials is the covering power of the developed photographic layers. This covering power can be determined by the structure of the devel oped silver. It is well known that the structure of the silver filaments is strongly affected by the surface properties of the developing grain. One o f the methods of changing these properties is epitaxial deposition of mixed halides onto the surface of the host grain. Transmitting electron microsco py was implemented to study this phenomenon. Double jet technique was used to introduce mixed silver chloride and bromide into the host emulsion conta ining pure silver bromide octahedral, cubic and other crystals. Surface pro perties of the host grains were thus altered in a significant way. This wor k presents the effect of these epitaxial depositions on the maximum optical density that was achieved upon coating the final emulsions as the light-se nsitive photographic layers.