Electrical Modulus and Dielectric Relaxation Studies on Solid Electrolyte System (BiI3)0.4-(Ag3PO4)0.6

Abstract

The a.c. impedance analysis technique has been used to investigate the dynamic and relaxation behavior of mobile Ag + ions in the case of the best conducting composition (BiI 3) 0.4-(Ag 3 PO 4) 0.6 which exhibited the highest value of electrical conductivity (3.0x10-3 S/cm) at room temperature (298 K) among the various compositions, previously examined by the authors, within a silver ion conducting multiphase system (BiI 3) x-(Ag 3 PO 4) (1-x) (where 0.1≤ x ≤ 0.9 mole fraction). The experimental data derived from a.c. impedance measurements carried out at various frequencies ranging from 20 Hz to 1 MHz over the temperature domain 298 to 433 K have revealed that the chosen solid electrolyte system exhibits an a.c. conductivity behavior in accordance with Jonscher's universal power law. The dielectric response and analyses of normalized impedance and modulus spectra tend to indicate the existence of more than one relaxation process occurring within the bulk material and confirm the superionic nature of the solid electrolyte sample (BiI 3) 0.4-(Ag 3 PO 4) 0.6 for feasible application in an all-solid-state electrochemical cell as well.