UNUSUAL TRANSPORT AND STRUCTURAL-PROPERTIES OF MECHANICALLY TREATED POLYCRYSTALLINE SILVER-IODIDE .1. IONIC-CONDUCTIVITY

It is shown that the increase in conductivity of polycrystalline silve r iodide due to its mechanical treatment can be attributed to the pres ence of metastable defects which are formed on mechanical treatment of AgI. Defects may be annealed by heating with the annealing rate depen ding on purity of AgI. The temperature dependence of conductivity for purified AgI has two temperature regions with different activation ene rgies: 0.3 and 0.5-0.6 eV at 350-400 K and below 350 K, respectively, which are interpreted in terms of the extrinsic-like conductivity acco mpanied by the defects 'freezing' process at lower temperatures. As it will be reported in the following parts of the paper devoted to diele ctric and structural studies of mechanically treated AgI, antiphase bo undaries formed in beta-gamma polytypes as a result of the treatment a re the most probable sources of metastable defects responsible for the conductivity enhancement observed.