engleski

Two-point dc ionic conductivity measurements in the superionic phase of Cu2−xSe

Abstract dc ionic conductivity (σi) of the mixed superionic conductor Cu2−xSe, with 0.01≤x≤0.26, is measured in the temperature range from 160 to 250 C. The new two-point measuring method is presented ; the experimental set-up is simplified and very small samples can be treated, which strongly increases the speed of the measurements. The temperature dependence of σi is found to be Arrhenius, with only weakly concentration- dependent activation energy A= 125±5 meV. For compositions x ≳ 0.1, the concentration dependence of σi is linear, σi∝(1 − 1.3x). As x is decreased from 0.1 to zero, σi is nonlinearly enhanced, which confirms the importance of ionic correlations in the mechanism of superionic conduction.

superionic conductor ; copper selenide ; ionic conductivity

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