Ionic conductivity and coulometric titration of copper selenide

The ionic conductivity of copper selenide was measured in the temperature range of 30-180°C by blocking the electronic current by the copper ion high conductivity solid electrolyte, 37CuBr·3[C ₆H ₁₂N ₂·2CH ₃Br]. It was found that the α-phase of Cu _2-δSe has a high ionic conductivity; for example, Cu _1.75Se exhibited an ionic conductivity of 3 × 10 ^-2 ohm ^-1cm ^-1 at room temperature. The coulometric titration of copper selenide was carried out with the help of the cell, Au/Cu _2-δSe/solid electrolyte/Cu; from the temperature dependence of the cell voltage, the β-α transition temperatures of Cu _2-δSe were determined as a function of δ.