Frequency-dependent (a) AC conductivity (, in Ω−1·m−1) as a function of (1000/T, in K−1) over the temperature range 373 to 973 K (100 to 700°C) and insets (b) and (c) showing frequency-dependent AC conductivity as a function of , in °C, in different temperature ranges for the rhombohedral PbNb2O6.
