Fig. 6(b) shows the temperature dependence of the dimensionless
figure of merit (ZT) of the CAO. The ZT value of the sample significantly
increased with the increasing temperature and reached a
maximum value of 9 103 at 1073 K. This value was larger than
that of the hot-pressed CuAl1xMgxO2 (x ¼ 0, 0.01, 0.02 and 0.05)
over the whole temperature range [25]. Thus, the CAO is a candidate
material for thermoelectric application at high temperature.