Electrical conductivity, thermo-electric power and structure of differently heat-treated CdO Original Research Article

The black coloured polymorph of cadmium oxide, that results from its heat treatment at 800°C, is shown to be about 1000 times more conducting than the usual yellowish brown CdO. The electrical conductivity of the 800°C-fired CdO shows a minimum at around 88 K. It is quite interesting that its thermo-electric power shows a change of slope also at around 88 K. The X-ray diffraction pattern of the as-supplied yellowish brown CdO has extra lines with respect to the patterns taken after 400 or 800°C firing.