Growth, Quality Characterization and Mechanical Hardness of DAST Crystals

4-N,N'-dimethylamino-N-methyl-4'-N'-stilbazolium tosylate crystals were grown by spontaneous crystallization and onto a seed using controlled slow cooling technique. The surface morphology of the grown crystals has been studied. As shown by X-ray diffraction analysis, the perfection of the structure of the grown plates depends on the method of obtaining them. The grown crystals were also characterized by the Vickers microhardness test and etching investigations. The values of microhardness for the crystals grown by spontaneous crystallization are found to exceed the corresponding values for the crystals grown onto a seed by 9-11%. There was established a correlation between the values of microhardness and the character of dislocations distribution in the crystals obtained by both methods. An assumption was made about the 4-N,N'-dimethylamino-N-methyl-4'-N'-stilbazolium tosylate deformation mechanism.