Preparation, Characterization of a New Fast Ionic Conductor [Ag2CdI4:0.x AgI]

An experimental attempt was made to characterize A new composite fast ionic systems, [Ag2CdI4:0.x AgI] (x=0.2, 0.4, 0.6 mol. wt. %), were prepared, using [Ag2Cd 4] mixed composite system as the host. [Ag2CdI4] compound belongs to the fast ion conductors of A2BX4 (A=Ag, Cu, B=Hg, Cd, Zn, Pb and others. The compound [Ag2CdI4] becomes superionic near 388K as the crystal lattice changes from a tetragonal to a hexagonal structure. Near 445 K, [Ag2CdI4] is replaced by an equilibrium mixture of α-AgI and CdI2. At each of these phase transition, ionic conductivity increases by an order of magnitude or more. The substitution of Cd2+ from Ag+ in [Ag2CdI4] is accompanied by a slight increase in the room temperature conductivity, as a result of either increased crystalline defects or an increased Ag+ substitution also characterized. X-ray powder diffraction, FTIR and Thermal (DTA, DSC, TGA) analyses were performed to confirm the formation of fast ion conductors [Ag2CdI4:0.x AgI].