Concentration polarization and ionic conductivity of nanocomposite thermoelectric materials K0.01Cu1.94S, K0.02Cu1.94S, K0.03Cu1.94S

Abstract

The paper presents experimental results of concentration polarization and ionic conductivity of nanocomposite thermoelectric materials K0.01Cu1.94S , K0.02Cu1.94S , K0.03Cu1.94S . According to X-ray phase analysis, the synthesized samples are monoclinic jarleite Cu1.93÷1.97S with an admixture of oxygen oxide Cu2S and monoclinic chalcocyte. High values of total ionic conductivity are observed, ranging from 0.86 to 1.5 Cm/cm. The lowest ionic conductivity (0.86 Cm/cm at 355 ◦ C) is observed for alloy K0.02Cu1.94S . In addition, it was found that with an increase in the concentration of potassium in the studied materials, ionic conductivity tends to decrease, activation energy increases, but the characteristics of ion transport remain high, corresponding to superionic materials.

Keywords

• ionic conductivity;
• nanocomposite;
• superionic semiconductors;
• activation energy