Abstract: A series of different tabular silver halide crystals with various distribution of iodide ions were prepared. Their sub-micro-structure analyses and semi-quantitative distribution of iodide ions in the microareas of a crystals were determined by the combination of scanning trans-inissive electron microscope (STEM) and energy dispersive X-ray spectrometer (EDS). The dielectric losses, Dember effect, HIRF and LIRF of tabular silver halide crystals with different structure were examined. The results showed that the ionic conductivity of the microcrystals, the effects of HIRF and LIRF, the photovoltage produced by Dember effect are different with different distribution of iodide ions. These results have a good corresponding relation with the photographic properties of the four kinds of emulsions.

Key words: tabular crystal, distribution of iodide ions, dielectric loss, Dember effect, HIRF and LIRF