A study in thermoelectric effect of Eu2O3 substitution on Al2O3 in CuAl(100−x)Eu(x)O2

The effects of Eu2O3 substitution on Al2O3 in CuAl(100−x) Eu(x)O2 (x = 0, 10, 30, 50, 70, and 100 mol%) were considered. In this study, all samples with a diameter of 20 mm were sintered by using solid-state reaction method. The structural analysis with XRD investigation shows that it had a hexagonal CuAlO2 structure at x = 0, 10, 30, and 50 mol%. Tetragonal CuEu2O4 structures were reported at x = 10, 30, 50, 70, and 100 mol%. The ZEM-3 instrument measures thermoelectric characteristics like the Seebeck coefficient, electrical resistivity, and power factor throughout the temperature range of 350 − 800 K. According to the investigation, the electrical resistivity value tended to continue to decrease as measurement temperature increased. The Seebeck coefficient shows a positive value. However, when Al2O3 was substituted for Eu2O3 in large amounts, the Seebeck coefficient value became negative. The power factor increases as the mole ratio of Eu2O3 increase, exhibited the highest value of around 9.50 µW mK−2 at 775 K.