Space charge depolarization of wurtzite or zinc blend structured silver iodide: modeling of preliminary studies

Mathematical modeling of a space charge depolarization of AgI in its ionic phase is reported. Initially, cell configuration of AgI sandwiched between two electronic conducting graphite electrodes were polarized by applying an external dc field ∼0.5 V across the cell. The depolarization potential time profile, instantly after the removal of external polarizing field, at various constant temperatures, below the structural phase transition temperature of ∼420 K of AgI is recorded. This is a characteristic temperature, as, the structural, electrical as well as thermodynamic properties of AgI are much different after (i.e. in α-AgI) and before this temperature (i.e. in β-AgI). The recorded profile is compared with the profiles obtained theoretically by considering different isothermal conditions. This study is limited to the isothermal variation of depolarization potential with time only, although this may also be a function of the position of ions inside the sample.