Electrical conductivity of CuBr in the temperature range 500–1050 K

Temperature dependence of the electric conductivity of the solid and liquid CuBr was determined by an AC technique. Results of measurements were registered in 5 s steps during heating and cooling of the samples. This permitted to obtain detailed runs of conductivity, including phase transformations: γ-CuBr ⇔ β-CuBr, β-CuBr ⇔ α-CuBr and α-CuBr ⇔ CuBrliquid. Pre-exponential factors and activation energies as well as charge diffusion coefficients in appropriate ranges of temperature were derived from measured conductivities, and transport properties in respective phases were discussed. Conductivity of molten CuBr was determined for the first time in a large temperature range 770–1050 K. Activation energy for conduction of molten CuBr and that of the superionic α-phase were found to be 2.28 ± 0.05 and 2.76 ± 0.16 kJ mol− 1, respectively. The latter value was obtained for the first time on the basis of a relatively large number of measurement points. Very high values of the conductivity of the α-phase and a decrease about 30% in the conductivity on melting, the largest that has ever been met among ionic conductors, were confirmed for the first time since the report of Tubandt et al. [C. Tubandt, J. Geiler and B. Baudouin, Landolt – Börnstein Physikalisch – chemische Tabellen, V.2, 5th ed., Springer, Berlin 1931, p. 1042.] and Tubandt and Geiler [C. Tubandt and J. Geiler, Landolt – Börnstein Physikalisch – chemische Tabellen, V.2, 5th ed., Springer, Berlin 1931, p. 1047].