Phase transition in a [Ag2HgI4:0.2AgI] mixed composite system doped with KI

A novel mixed composite system, [Ag2HgI4:0.2AgI]: (x) KI, (x = 0.2, 0.4, 0.6 mol %), was prepared and [Ag2HgI4:0.2AgI] composite system was used as the host. Electrical conductivity was measured to study the transition behavior at frequencies of 100, 120 Hz, 1, and 10 kHz in the temperature range of 90-170A degrees C. Conductivity increased sharply during the alpha-beta phase transition. Upon increasing the dopant-to-host ratio, the conductivity of the superionic system exhibited Arrhenius (thermally activated)-type behavior. X-ray powder diffraction, DTA, DTG and TGA were performed to confirm the doping effect and transition in the host. The phase transition temperature decreased with an increase in the dopant concentration. Activation energies in eV for pre- and post-transition phase behavior are also reported.