Abstract: A Series of multistructure tabular iodobromide microcrystais with the same content and the different distribution of iodide ions were prepared by double-jet precipitation. The distribution of iodide ions in the microareas of a crystal was measured by the means of combination of scanning transmissive electron microscope (STEM) and energy dispersive X-ray spectrometer (EDS). It was found that the iodide ions are distributed in different layers of a tabular microcrystal as designed, The results of EDS also showed the migration of iodide ions from the iodide-enriched layer to the pure AgBr layer. The higher the iodide ions are concentrated in the iodideenruched layer, the more the iodide ions migrate from this layer to the pure AgBr layer.The relations between structures and properties of multistructure tabular microcrystals were studied by the methods of dielectric loss, Dember effect and surface development, The results showed that the microcrystal, multistrucures affect apperently their photo-physical properties, as ionic conductivity, Dember photovoltage, and the latent image of multistructure tabular microcrystals always forms preferentially in the pure AgBr or iodide-lacked layers.

Key words: multistructure tabular microcrystal, distribution of iodide ions, energy disperce spectroscopy. dielectric loss. Dember effect, surface deveropment