Research of new AgX crystal forms by transmission electron microscopy

The research of AgX (X=Cl, Br) crystals grown from ammonia solution as a function of X- supersaturation, gelatin concentration, temperature, and use of growth modificators, has been enhanced by data from transmission electron microscopy. The study resulted in preparing AgBr thin films with the most developed ¿100¿ side of rombododecahedron. The size of the crystals was 5 x 15 mm. The thickness was several microm. The new forms of AgBr and AgCl microcrystals were obtained from a high concentrated solution of the corresponding salts in NH4OH. These microcrystals were named "X," 'Y' crystals [AgBr] and stereostructures [AgCl] deriving from their external shapes. As a result of the variation of crystallization parameters, six various morphological types of stereostructures, distinguishable by the size of a central element in relation to external elements and a length of a binding element, were seen. Experiments on photolysis of the stereostructures at the substrate temperature 25-200 degrees C were carried out in vacuum. Exposure to mercury lamp light resulted in characteristic location of large particles of photolytic silver on the stereostructure surface, depending on substrate temperature.