Investigation of the system AgBr–AgI optical materials volt-ampere characteristics

IR light guides based on crystals and ceramics of the AgBr–AgI system are transparent in the mid-infrared range from 2 to 25 $\mu$m, which is in demand for thermal imaging, laser technology and spectroscopy. High photo- and radiation resistance makes these materials particularly attractive. For the design of optical equipment, information is needed on the electrical properties of the material, which are most fully characterized by the current-voltage characteristic (VAC). In this work, the dependence of VAC of the studied materials in the range of compositions from 5 to 80 mol.% AgI in the system AgBr–AgI on the composition of the material and temperature in the range of 298–453 K. It has been established that an increase in the iodine content for crystalline materials of AgBr–AgI systems leads to a decrease in electrical conductivity. The values of specific conductivity under equal conditions (the same temperature and the same applied voltage) for ceramics of the AgBr–AgI system are two to three orders of magnitude higher than for crystals. The values of specific conductivity for ceramics are at the level of conductivity of solid electrolytes. At the temperature of the $\beta$–AgI–$\alpha$–AgI phase transition in ceramics of the AgBr–AgI systems, a jump in conductivity is observed, which is explained by the $\beta$–AgI–$\alpha$–AgI phase transition.