Phase transition and copper ion conductor in PbBr2-CuBr

The solid solution of PbBr₂-CuBr has a high electric conductivity above 150 °C. The frequency and temperature dependences of complex dielectric constants have been investigated in the concentration of x=0.01-0.3. They exhibited a strong dieletric relaxation caused by the ionic conduction. Specific heat capacities have been measured in the temperature range from 100 to 200 °C. They showed no anomalous specific heat at the temperature 150 °C, but a distinct peak of heat was found at about 170 °C depending on the concentration. Using the simplified model of disorder of mobile ions, the excess specific heat was explained as the transition of copper ions between two sites. Paper presented at the 4th Euroconference on Solid State Ionics, Renvyle, Galway, Ireland, Sept. 13–19, 1997